Canvas
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2024-02-26 22:45:46
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Canvas 源码:
/**
* The Canvas class holds the "draw" calls. To draw something, you need
* 4 basic components: A Bitmap to hold the pixels, a Canvas to host
* the draw calls (writing into the bitmap), a drawing primitive (e.g. Rect,
* Path, text, Bitmap), and a paint (to describe the colors and styles for the
* drawing).
*
* <div class="special reference">
* <h3>Developer Guides</h3>
* <p>For more information about how to use Canvas, read the
* <a href="{@docRoot}guide/topics/graphics/2d-graphics.html">
* Canvas and Drawables</a> developer guide.</p></div>
*/
public class Canvas extends BaseCanvas {
private static int sCompatiblityVersion = 0;
/** @hide */
public static boolean sCompatibilityRestore = false;
/** @hide */
public static boolean sCompatibilitySetBitmap = false;
/** @hide */
public long getNativeCanvasWrapper() {
return mNativeCanvasWrapper;
}
/** @hide */
public boolean isRecordingFor(Object o) { return false; }
// may be null
private Bitmap mBitmap;
// optional field set by the caller
private DrawFilter mDrawFilter;
// Maximum bitmap size as defined in Skia's native code
// (see SkCanvas.cpp, SkDraw.cpp)
private static final int MAXMIMUM_BITMAP_SIZE = 32766;
// The approximate size of the native allocation associated with
// a Canvas object.
private static final long NATIVE_ALLOCATION_SIZE = 525;
// Use a Holder to allow static initialization of Canvas in the boot image.
private static class NoImagePreloadHolder {
public static final NativeAllocationRegistry sRegistry = new NativeAllocationRegistry(
Canvas.class.getClassLoader(), nGetNativeFinalizer(), NATIVE_ALLOCATION_SIZE);
}
// This field is used to finalize the native Canvas properly
private Runnable mFinalizer;
/**
* Construct an empty raster canvas. Use setBitmap() to specify a bitmap to
* draw into. The initial target density is {@link Bitmap#DENSITY_NONE};
* this will typically be replaced when a target bitmap is set for the
* canvas.
*/
public Canvas() {
if (!isHardwareAccelerated()) {
// 0 means no native bitmap
mNativeCanvasWrapper = nInitRaster(null);
mFinalizer = NoImagePreloadHolder.sRegistry.registerNativeAllocation(
this, mNativeCanvasWrapper);
} else {
mFinalizer = null;
}
}
/**
* Construct a canvas with the specified bitmap to draw into. The bitmap
* must be mutable.
*
* <p>The initial target density of the canvas is the same as the given
* bitmap's density.
*
* @param bitmap Specifies a mutable bitmap for the canvas to draw into.
*/
public Canvas(@NonNull Bitmap bitmap) {
if (!bitmap.isMutable()) {
throw new IllegalStateException("Immutable bitmap passed to Canvas constructor");
}
throwIfCannotDraw(bitmap);
mNativeCanvasWrapper = nInitRaster(bitmap);
mFinalizer = NoImagePreloadHolder.sRegistry.registerNativeAllocation(
this, mNativeCanvasWrapper);
mBitmap = bitmap;
mDensity = bitmap.mDensity;
}
/** @hide */
public Canvas(long nativeCanvas) {
if (nativeCanvas == 0) {
throw new IllegalStateException();
}
mNativeCanvasWrapper = nativeCanvas;
mFinalizer = NoImagePreloadHolder.sRegistry.registerNativeAllocation(
this, mNativeCanvasWrapper);
mDensity = Bitmap.getDefaultDensity();
}
/**
* Returns null.
*
* @deprecated This method is not supported and should not be invoked.
*
* @hide
*/
@Deprecated
protected GL getGL() {
return null;
}
/**
* Indicates whether this Canvas uses hardware acceleration.
*
* Note that this method does not define what type of hardware acceleration
* may or may not be used.
*
* @return True if drawing operations are hardware accelerated,
* false otherwise.
*/
public boolean isHardwareAccelerated() {
return false;
}
/**
* Specify a bitmap for the canvas to draw into. All canvas state such as
* layers, filters, and the save/restore stack are reset. Additionally,
* the canvas' target density is updated to match that of the bitmap.
*
* Prior to API level {@value Build.VERSION_CODES#O} the current matrix and
* clip stack were preserved.
*
* @param bitmap Specifies a mutable bitmap for the canvas to draw into.
* @see #setDensity(int)
* @see #getDensity()
*/
public void setBitmap(@Nullable Bitmap bitmap) {
if (isHardwareAccelerated()) {
throw new RuntimeException("Can't set a bitmap device on a HW accelerated canvas");
}
Matrix preservedMatrix = null;
if (bitmap != null && sCompatibilitySetBitmap) {
preservedMatrix = getMatrix();
}
if (bitmap == null) {
nSetBitmap(mNativeCanvasWrapper, null);
mDensity = Bitmap.DENSITY_NONE;
} else {
if (!bitmap.isMutable()) {
throw new IllegalStateException();
}
throwIfCannotDraw(bitmap);
nSetBitmap(mNativeCanvasWrapper, bitmap);
mDensity = bitmap.mDensity;
}
if (preservedMatrix != null) {
setMatrix(preservedMatrix);
}
mBitmap = bitmap;
}
/** @hide */
public void insertReorderBarrier() {}
/** @hide */
public void insertInorderBarrier() {}
/**
* Return true if the device that the current layer draws into is opaque
* (i.e. does not support per-pixel alpha).
*
* @return true if the device that the current layer draws into is opaque
*/
public boolean isOpaque() {
return nIsOpaque(mNativeCanvasWrapper);
}
/**
* Returns the width of the current drawing layer
*
* @return the width of the current drawing layer
*/
public int getWidth() {
return nGetWidth(mNativeCanvasWrapper);
}
/**
* Returns the height of the current drawing layer
*
* @return the height of the current drawing layer
*/
public int getHeight() {
return nGetHeight(mNativeCanvasWrapper);
}
/**
* <p>Returns the target density of the canvas. The default density is
* derived from the density of its backing bitmap, or
* {@link Bitmap#DENSITY_NONE} if there is not one.</p>
*
* @return Returns the current target density of the canvas, which is used
* to determine the scaling factor when drawing a bitmap into it.
*
* @see #setDensity(int)
* @see Bitmap#getDensity()
*/
public int getDensity() {
return mDensity;
}
/**
* <p>Specifies the density for this Canvas' backing bitmap. This modifies
* the target density of the canvas itself, as well as the density of its
* backing bitmap via {@link Bitmap#setDensity(int) Bitmap.setDensity(int)}.
*
* @param density The new target density of the canvas, which is used
* to determine the scaling factor when drawing a bitmap into it. Use
* {@link Bitmap#DENSITY_NONE} to disable bitmap scaling.
*
* @see #getDensity()
* @see Bitmap#setDensity(int)
*/
public void setDensity(int density) {
if (mBitmap != null) {
mBitmap.setDensity(density);
}
mDensity = density;
}
/** @hide */
public void setScreenDensity(int density) {
mScreenDensity = density;
}
/**
* Returns the maximum allowed width for bitmaps drawn with this canvas.
* Attempting to draw with a bitmap wider than this value will result
* in an error.
*
* @see #getMaximumBitmapHeight()
*/
public int getMaximumBitmapWidth() {
return MAXMIMUM_BITMAP_SIZE;
}
/**
* Returns the maximum allowed height for bitmaps drawn with this canvas.
* Attempting to draw with a bitmap taller than this value will result
* in an error.
*
* @see #getMaximumBitmapWidth()
*/
public int getMaximumBitmapHeight() {
return MAXMIMUM_BITMAP_SIZE;
}
// the SAVE_FLAG constants must match their native equivalents
/** @hide */
@IntDef(flag = true,
value = {
ALL_SAVE_FLAG
})
@Retention(RetentionPolicy.SOURCE)
public @interface Saveflags {}
/**
* Restore the current matrix when restore() is called.
* @removed
* @deprecated Use the flagless version of {@link #save()}, {@link #saveLayer(RectF, Paint)} or
* {@link #saveLayerAlpha(RectF, int)}. For saveLayer() calls the matrix
* was always restored for {@link #isHardwareAccelerated() Hardware accelerated}
* canvases and as of API level {@value Build.VERSION_CODES#O} that is the default
* behavior for all canvas types.
*/
public static final int MATRIX_SAVE_FLAG = 0x01;
/**
* Restore the current clip when restore() is called.
*
* @removed
* @deprecated Use the flagless version of {@link #save()}, {@link #saveLayer(RectF, Paint)} or
* {@link #saveLayerAlpha(RectF, int)}. For saveLayer() calls the clip
* was always restored for {@link #isHardwareAccelerated() Hardware accelerated}
* canvases and as of API level {@value Build.VERSION_CODES#O} that is the default
* behavior for all canvas types.
*/
public static final int CLIP_SAVE_FLAG = 0x02;
/**
* The layer requires a per-pixel alpha channel.
*
* @removed
* @deprecated This flag is ignored. Use the flagless version of {@link #saveLayer(RectF, Paint)}
* {@link #saveLayerAlpha(RectF, int)}.
*/
public static final int HAS_ALPHA_LAYER_SAVE_FLAG = 0x04;
/**
* The layer requires full 8-bit precision for each color channel.
*
* @removed
* @deprecated This flag is ignored. Use the flagless version of {@link #saveLayer(RectF, Paint)}
* {@link #saveLayerAlpha(RectF, int)}.
*/
public static final int FULL_COLOR_LAYER_SAVE_FLAG = 0x08;
/**
* Clip drawing to the bounds of the offscreen layer, omit at your own peril.
* <p class="note"><strong>Note:</strong> it is strongly recommended to not
* omit this flag for any call to <code>saveLayer()</code> and
* <code>saveLayerAlpha()</code> variants. Not passing this flag generally
* triggers extremely poor performance with hardware accelerated rendering.
*
* @removed
* @deprecated This flag results in poor performance and the same effect can be achieved with
* a single layer or multiple draw commands with different clips.
*
*/
public static final int CLIP_TO_LAYER_SAVE_FLAG = 0x10;
/**
* Restore everything when restore() is called (standard save flags).
* <p class="note"><strong>Note:</strong> for performance reasons, it is
* strongly recommended to pass this - the complete set of flags - to any
* call to <code>saveLayer()</code> and <code>saveLayerAlpha()</code>
* variants.
*
* <p class="note"><strong>Note:</strong> all methods that accept this flag
* have flagless versions that are equivalent to passing this flag.
*/
public static final int ALL_SAVE_FLAG = 0x1F;
private static void checkValidSaveFlags(int saveFlags) {
if (sCompatiblityVersion >= Build.VERSION_CODES.P
&& saveFlags != ALL_SAVE_FLAG) {
throw new IllegalArgumentException(
"Invalid Layer Save Flag - only ALL_SAVE_FLAGS is allowed");
}
}
/**
* Saves the current matrix and clip onto a private stack.
* <p>
* Subsequent calls to translate,scale,rotate,skew,concat or clipRect,
* clipPath will all operate as usual, but when the balancing call to
* restore() is made, those calls will be forgotten, and the settings that
* existed before the save() will be reinstated.
*
* @return The value to pass to restoreToCount() to balance this save()
*/
public int save() {
return nSave(mNativeCanvasWrapper, MATRIX_SAVE_FLAG | CLIP_SAVE_FLAG);
}
/**
* Based on saveFlags, can save the current matrix and clip onto a private
* stack.
* <p class="note"><strong>Note:</strong> if possible, use the
* parameter-less save(). It is simpler and faster than individually
* disabling the saving of matrix or clip with this method.
* <p>
* Subsequent calls to translate,scale,rotate,skew,concat or clipRect,
* clipPath will all operate as usual, but when the balancing call to
* restore() is made, those calls will be forgotten, and the settings that
* existed before the save() will be reinstated.
*
* @removed
* @deprecated Use {@link #save()} instead.
* @param saveFlags flag bits that specify which parts of the Canvas state
* to save/restore
* @return The value to pass to restoreToCount() to balance this save()
*/
public int save(@Saveflags int saveFlags) {
return nSave(mNativeCanvasWrapper, saveFlags);
}
/**
* This behaves the same as save(), but in addition it allocates and
* redirects drawing to an offscreen bitmap.
* <p class="note"><strong>Note:</strong> this method is very expensive,
* incurring more than double rendering cost for contained content. Avoid
* using this method, especially if the bounds provided are large. It is
* recommended to use a {@link android.view.View#LAYER_TYPE_HARDWARE hardware layer} on a View
* to apply an xfermode, color filter, or alpha, as it will perform much
* better than this method.
* <p>
* All drawing calls are directed to a newly allocated offscreen bitmap.
* Only when the balancing call to restore() is made, is that offscreen
* buffer drawn back to the current target of the Canvas (either the
* screen, it's target Bitmap, or the previous layer).
* <p>
* Attributes of the Paint - {@link Paint#getAlpha() alpha},
* {@link Paint#getXfermode() Xfermode}, and
* {@link Paint#getColorFilter() ColorFilter} are applied when the
* offscreen bitmap is drawn back when restore() is called.
*
* As of API Level API level {@value Build.VERSION_CODES#P} the only valid
* {@code saveFlags} is {@link #ALL_SAVE_FLAG}. All other flags are ignored.
*
* @deprecated Use {@link #saveLayer(RectF, Paint)} instead.
* @param bounds May be null. The maximum size the offscreen bitmap
* needs to be (in local coordinates)
* @param paint This is copied, and is applied to the offscreen when
* restore() is called.
* @param saveFlags see _SAVE_FLAG constants, generally {@link #ALL_SAVE_FLAG} is recommended
* for performance reasons.
* @return value to pass to restoreToCount() to balance this save()
*/
public int saveLayer(@Nullable RectF bounds, @Nullable Paint paint, @Saveflags int saveFlags) {
if (bounds == null) {
bounds = new RectF(getClipBounds());
}
checkValidSaveFlags(saveFlags);
return saveLayer(bounds.left, bounds.top, bounds.right, bounds.bottom, paint,
ALL_SAVE_FLAG);
}
/**
* This behaves the same as save(), but in addition it allocates and
* redirects drawing to an offscreen rendering target.
* <p class="note"><strong>Note:</strong> this method is very expensive,
* incurring more than double rendering cost for contained content. Avoid
* using this method when possible and instead use a
* {@link android.view.View#LAYER_TYPE_HARDWARE hardware layer} on a View
* to apply an xfermode, color filter, or alpha, as it will perform much
* better than this method.
* <p>
* All drawing calls are directed to a newly allocated offscreen rendering target.
* Only when the balancing call to restore() is made, is that offscreen
* buffer drawn back to the current target of the Canvas (which can potentially be a previous
* layer if these calls are nested).
* <p>
* Attributes of the Paint - {@link Paint#getAlpha() alpha},
* {@link Paint#getXfermode() Xfermode}, and
* {@link Paint#getColorFilter() ColorFilter} are applied when the
* offscreen rendering target is drawn back when restore() is called.
*
* @param bounds May be null. The maximum size the offscreen render target
* needs to be (in local coordinates)
* @param paint This is copied, and is applied to the offscreen when
* restore() is called.
* @return value to pass to restoreToCount() to balance this save()
*/
public int saveLayer(@Nullable RectF bounds, @Nullable Paint paint) {
return saveLayer(bounds, paint, ALL_SAVE_FLAG);
}
/**
* @hide
*/
public int saveUnclippedLayer(int left, int top, int right, int bottom) {
return nSaveLayer(mNativeCanvasWrapper, left, top, right, bottom, 0, 0);
}
/**
* Helper version of saveLayer() that takes 4 values rather than a RectF.
*
* As of API Level API level {@value Build.VERSION_CODES#P} the only valid
* {@code saveFlags} is {@link #ALL_SAVE_FLAG}. All other flags are ignored.
*
* @deprecated Use {@link #saveLayer(float, float, float, float, Paint)} instead.
*/
public int saveLayer(float left, float top, float right, float bottom, @Nullable Paint paint,
@Saveflags int saveFlags) {
checkValidSaveFlags(saveFlags);
return nSaveLayer(mNativeCanvasWrapper, left, top, right, bottom,
paint != null ? paint.getNativeInstance() : 0,
ALL_SAVE_FLAG);
}
/**
* Convenience for {@link #saveLayer(RectF, Paint)} that takes the four float coordinates of the
* bounds rectangle.
*/
public int saveLayer(float left, float top, float right, float bottom, @Nullable Paint paint) {
return saveLayer(left, top, right, bottom, paint, ALL_SAVE_FLAG);
}
/**
* This behaves the same as save(), but in addition it allocates and
* redirects drawing to an offscreen bitmap.
* <p class="note"><strong>Note:</strong> this method is very expensive,
* incurring more than double rendering cost for contained content. Avoid
* using this method, especially if the bounds provided are large. It is
* recommended to use a {@link android.view.View#LAYER_TYPE_HARDWARE hardware layer} on a View
* to apply an xfermode, color filter, or alpha, as it will perform much
* better than this method.
* <p>
* All drawing calls are directed to a newly allocated offscreen bitmap.
* Only when the balancing call to restore() is made, is that offscreen
* buffer drawn back to the current target of the Canvas (either the
* screen, it's target Bitmap, or the previous layer).
* <p>
* The {@code alpha} parameter is applied when the offscreen bitmap is
* drawn back when restore() is called.
*
* As of API Level API level {@value Build.VERSION_CODES#P} the only valid
* {@code saveFlags} is {@link #ALL_SAVE_FLAG}. All other flags are ignored.
*
* @deprecated Use {@link #saveLayerAlpha(RectF, int)} instead.
* @param bounds The maximum size the offscreen bitmap needs to be
* (in local coordinates)
* @param alpha The alpha to apply to the offscreen when it is
drawn during restore()
* @param saveFlags see _SAVE_FLAG constants, generally {@link #ALL_SAVE_FLAG} is recommended
* for performance reasons.
* @return value to pass to restoreToCount() to balance this call
*/
public int saveLayerAlpha(@Nullable RectF bounds, int alpha, @Saveflags int saveFlags) {
if (bounds == null) {
bounds = new RectF(getClipBounds());
}
checkValidSaveFlags(saveFlags);
return saveLayerAlpha(bounds.left, bounds.top, bounds.right, bounds.bottom, alpha,
ALL_SAVE_FLAG);
}
/**
* Convenience for {@link #saveLayer(RectF, Paint)} but instead of taking a entire Paint object
* it takes only the {@code alpha} parameter.
*
* @param bounds The maximum size the offscreen bitmap needs to be
* (in local coordinates)
* @param alpha The alpha to apply to the offscreen when it is
drawn during restore()
*/
public int saveLayerAlpha(@Nullable RectF bounds, int alpha) {
return saveLayerAlpha(bounds, alpha, ALL_SAVE_FLAG);
}
/**
* Helper for saveLayerAlpha() that takes 4 values instead of a RectF.
*
* As of API Level API level {@value Build.VERSION_CODES#P} the only valid
* {@code saveFlags} is {@link #ALL_SAVE_FLAG}. All other flags are ignored.
*
* @deprecated Use {@link #saveLayerAlpha(float, float, float, float, int)} instead.
*/
public int saveLayerAlpha(float left, float top, float right, float bottom, int alpha,
@Saveflags int saveFlags) {
checkValidSaveFlags(saveFlags);
alpha = Math.min(255, Math.max(0, alpha));
return nSaveLayerAlpha(mNativeCanvasWrapper, left, top, right, bottom,
alpha, ALL_SAVE_FLAG);
}
/**
* Convenience for {@link #saveLayerAlpha(RectF, int)} that takes the four float coordinates of
* the bounds rectangle.
*/
public int saveLayerAlpha(float left, float top, float right, float bottom, int alpha) {
return saveLayerAlpha(left, top, right, bottom, alpha, ALL_SAVE_FLAG);
}
/**
* This call balances a previous call to save(), and is used to remove all
* modifications to the matrix/clip state since the last save call. It is
* an error to call restore() more times than save() was called.
*/
public void restore() {
if (!nRestore(mNativeCanvasWrapper)
&& (!sCompatibilityRestore || !isHardwareAccelerated())) {
throw new IllegalStateException("Underflow in restore - more restores than saves");
}
}
/**
* Returns the number of matrix/clip states on the Canvas' private stack.
* This will equal # save() calls - # restore() calls.
*/
public int getSaveCount() {
return nGetSaveCount(mNativeCanvasWrapper);
}
/**
* Efficient way to pop any calls to save() that happened after the save
* count reached saveCount. It is an error for saveCount to be less than 1.
*
* Example:
* int count = canvas.save();
* ... // more calls potentially to save()
* canvas.restoreToCount(count);
* // now the canvas is back in the same state it was before the initial
* // call to save().
*
* @param saveCount The save level to restore to.
*/
public void restoreToCount(int saveCount) {
if (saveCount < 1) {
if (!sCompatibilityRestore || !isHardwareAccelerated()) {
// do nothing and throw without restoring
throw new IllegalArgumentException(
"Underflow in restoreToCount - more restores than saves");
}
// compat behavior - restore as far as possible
saveCount = 1;
}
nRestoreToCount(mNativeCanvasWrapper, saveCount);
}
/**
* Preconcat the current matrix with the specified translation
*
* @param dx The distance to translate in X
* @param dy The distance to translate in Y
*/
public void translate(float dx, float dy) {
if (dx == 0.0f && dy == 0.0f) return;
nTranslate(mNativeCanvasWrapper, dx, dy);
}
/**
* Preconcat the current matrix with the specified scale.
*
* @param sx The amount to scale in X
* @param sy The amount to scale in Y
*/
public void scale(float sx, float sy) {
if (sx == 1.0f && sy == 1.0f) return;
nScale(mNativeCanvasWrapper, sx, sy);
}
/**
* Preconcat the current matrix with the specified scale.
*
* @param sx The amount to scale in X
* @param sy The amount to scale in Y
* @param px The x-coord for the pivot point (unchanged by the scale)
* @param py The y-coord for the pivot point (unchanged by the scale)
*/
public final void scale(float sx, float sy, float px, float py) {
if (sx == 1.0f && sy == 1.0f) return;
translate(px, py);
scale(sx, sy);
translate(-px, -py);
}
/**
* Preconcat the current matrix with the specified rotation.
*
* @param degrees The amount to rotate, in degrees
*/
public void rotate(float degrees) {
if (degrees == 0.0f) return;
nRotate(mNativeCanvasWrapper, degrees);
}
/**
* Preconcat the current matrix with the specified rotation.
*
* @param degrees The amount to rotate, in degrees
* @param px The x-coord for the pivot point (unchanged by the rotation)
* @param py The y-coord for the pivot point (unchanged by the rotation)
*/
public final void rotate(float degrees, float px, float py) {
if (degrees == 0.0f) return;
translate(px, py);
rotate(degrees);
translate(-px, -py);
}
/**
* Preconcat the current matrix with the specified skew.
*
* @param sx The amount to skew in X
* @param sy The amount to skew in Y
*/
public void skew(float sx, float sy) {
if (sx == 0.0f && sy == 0.0f) return;
nSkew(mNativeCanvasWrapper, sx, sy);
}
/**
* Preconcat the current matrix with the specified matrix. If the specified
* matrix is null, this method does nothing.
*
* @param matrix The matrix to preconcatenate with the current matrix
*/
public void concat(@Nullable Matrix matrix) {
if (matrix != null) nConcat(mNativeCanvasWrapper, matrix.native_instance);
}
/**
* Completely replace the current matrix with the specified matrix. If the
* matrix parameter is null, then the current matrix is reset to identity.
*
* <strong>Note:</strong> it is recommended to use {@link #concat(Matrix)},
* {@link #scale(float, float)}, {@link #translate(float, float)} and
* {@link #rotate(float)} instead of this method.
*
* @param matrix The matrix to replace the current matrix with. If it is
* null, set the current matrix to identity.
*
* @see #concat(Matrix)
*/
public void setMatrix(@Nullable Matrix matrix) {
nSetMatrix(mNativeCanvasWrapper,
matrix == null ? 0 : matrix.native_instance);
}
/**
* Return, in ctm, the current transformation matrix. This does not alter
* the matrix in the canvas, but just returns a copy of it.
*
* @deprecated {@link #isHardwareAccelerated() Hardware accelerated} canvases may have any
* matrix when passed to a View or Drawable, as it is implementation defined where in the
* hierarchy such canvases are created. It is recommended in such cases to either draw contents
* irrespective of the current matrix, or to track relevant transform state outside of the
* canvas.
*/
@Deprecated
public void getMatrix(@NonNull Matrix ctm) {
nGetMatrix(mNativeCanvasWrapper, ctm.native_instance);
}
/**
* Return a new matrix with a copy of the canvas' current transformation
* matrix.
*
* @deprecated {@link #isHardwareAccelerated() Hardware accelerated} canvases may have any
* matrix when passed to a View or Drawable, as it is implementation defined where in the
* hierarchy such canvases are created. It is recommended in such cases to either draw contents
* irrespective of the current matrix, or to track relevant transform state outside of the
* canvas.
*/
@Deprecated
public final @NonNull Matrix getMatrix() {
Matrix m = new Matrix();
//noinspection deprecation
getMatrix(m);
return m;
}
private static void checkValidClipOp(@NonNull Region.Op op) {
if (sCompatiblityVersion >= Build.VERSION_CODES.P
&& op != Region.Op.INTERSECT && op != Region.Op.DIFFERENCE) {
throw new IllegalArgumentException(
"Invalid Region.Op - only INTERSECT and DIFFERENCE are allowed");
}
}
/**
* Modify the current clip with the specified rectangle.
*
* @param rect The rect to intersect with the current clip
* @param op How the clip is modified
* @return true if the resulting clip is non-empty
*
* @deprecated Region.Op values other than {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} have the ability to expand the clip. The canvas clipping APIs
* are intended to only expand the clip as a result of a restore operation. This enables a view
* parent to clip a canvas to clearly define the maximal drawing area of its children. The
* recommended alternative calls are {@link #clipRect(RectF)} and {@link #clipOutRect(RectF)};
*
* As of API Level API level {@value Build.VERSION_CODES#P} only {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} are valid Region.Op parameters.
*/
@Deprecated
public boolean clipRect(@NonNull RectF rect, @NonNull Region.Op op) {
checkValidClipOp(op);
return nClipRect(mNativeCanvasWrapper, rect.left, rect.top, rect.right, rect.bottom,
op.nativeInt);
}
/**
* Modify the current clip with the specified rectangle, which is
* expressed in local coordinates.
*
* @param rect The rectangle to intersect with the current clip.
* @param op How the clip is modified
* @return true if the resulting clip is non-empty
*
* @deprecated Region.Op values other than {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} have the ability to expand the clip. The canvas clipping APIs
* are intended to only expand the clip as a result of a restore operation. This enables a view
* parent to clip a canvas to clearly define the maximal drawing area of its children. The
* recommended alternative calls are {@link #clipRect(Rect)} and {@link #clipOutRect(Rect)};
*
* As of API Level API level {@value Build.VERSION_CODES#P} only {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} are valid Region.Op parameters.
*/
@Deprecated
public boolean clipRect(@NonNull Rect rect, @NonNull Region.Op op) {
checkValidClipOp(op);
return nClipRect(mNativeCanvasWrapper, rect.left, rect.top, rect.right, rect.bottom,
op.nativeInt);
}
/**
* DON'T USE THIS METHOD. It exists only to support a particular legacy behavior in
* the view system and will be removed as soon as that code is refactored to no longer
* depend on this behavior.
* @hide
*/
public boolean clipRectUnion(@NonNull Rect rect) {
return nClipRect(mNativeCanvasWrapper, rect.left, rect.top, rect.right, rect.bottom,
Region.Op.UNION.nativeInt);
}
/**
* Intersect the current clip with the specified rectangle, which is
* expressed in local coordinates.
*
* @param rect The rectangle to intersect with the current clip.
* @return true if the resulting clip is non-empty
*/
public boolean clipRect(@NonNull RectF rect) {
return nClipRect(mNativeCanvasWrapper, rect.left, rect.top, rect.right, rect.bottom,
Region.Op.INTERSECT.nativeInt);
}
/**
* Set the clip to the difference of the current clip and the specified rectangle, which is
* expressed in local coordinates.
*
* @param rect The rectangle to perform a difference op with the current clip.
* @return true if the resulting clip is non-empty
*/
public boolean clipOutRect(@NonNull RectF rect) {
return nClipRect(mNativeCanvasWrapper, rect.left, rect.top, rect.right, rect.bottom,
Region.Op.DIFFERENCE.nativeInt);
}
/**
* Intersect the current clip with the specified rectangle, which is
* expressed in local coordinates.
*
* @param rect The rectangle to intersect with the current clip.
* @return true if the resulting clip is non-empty
*/
public boolean clipRect(@NonNull Rect rect) {
return nClipRect(mNativeCanvasWrapper, rect.left, rect.top, rect.right, rect.bottom,
Region.Op.INTERSECT.nativeInt);
}
/**
* Set the clip to the difference of the current clip and the specified rectangle, which is
* expressed in local coordinates.
*
* @param rect The rectangle to perform a difference op with the current clip.
* @return true if the resulting clip is non-empty
*/
public boolean clipOutRect(@NonNull Rect rect) {
return nClipRect(mNativeCanvasWrapper, rect.left, rect.top, rect.right, rect.bottom,
Region.Op.DIFFERENCE.nativeInt);
}
/**
* Modify the current clip with the specified rectangle, which is
* expressed in local coordinates.
*
* @param left The left side of the rectangle to intersect with the
* current clip
* @param top The top of the rectangle to intersect with the current
* clip
* @param right The right side of the rectangle to intersect with the
* current clip
* @param bottom The bottom of the rectangle to intersect with the current
* clip
* @param op How the clip is modified
* @return true if the resulting clip is non-empty
*
* @deprecated Region.Op values other than {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} have the ability to expand the clip. The canvas clipping APIs
* are intended to only expand the clip as a result of a restore operation. This enables a view
* parent to clip a canvas to clearly define the maximal drawing area of its children. The
* recommended alternative calls are {@link #clipRect(float,float,float,float)} and
* {@link #clipOutRect(float,float,float,float)};
*
* As of API Level API level {@value Build.VERSION_CODES#P} only {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} are valid Region.Op parameters.
*/
@Deprecated
public boolean clipRect(float left, float top, float right, float bottom,
@NonNull Region.Op op) {
checkValidClipOp(op);
return nClipRect(mNativeCanvasWrapper, left, top, right, bottom, op.nativeInt);
}
/**
* Intersect the current clip with the specified rectangle, which is
* expressed in local coordinates.
*
* @param left The left side of the rectangle to intersect with the
* current clip
* @param top The top of the rectangle to intersect with the current clip
* @param right The right side of the rectangle to intersect with the
* current clip
* @param bottom The bottom of the rectangle to intersect with the current
* clip
* @return true if the resulting clip is non-empty
*/
public boolean clipRect(float left, float top, float right, float bottom) {
return nClipRect(mNativeCanvasWrapper, left, top, right, bottom,
Region.Op.INTERSECT.nativeInt);
}
/**
* Set the clip to the difference of the current clip and the specified rectangle, which is
* expressed in local coordinates.
*
* @param left The left side of the rectangle used in the difference operation
* @param top The top of the rectangle used in the difference operation
* @param right The right side of the rectangle used in the difference operation
* @param bottom The bottom of the rectangle used in the difference operation
* @return true if the resulting clip is non-empty
*/
public boolean clipOutRect(float left, float top, float right, float bottom) {
return nClipRect(mNativeCanvasWrapper, left, top, right, bottom,
Region.Op.DIFFERENCE.nativeInt);
}
/**
* Intersect the current clip with the specified rectangle, which is
* expressed in local coordinates.
*
* @param left The left side of the rectangle to intersect with the
* current clip
* @param top The top of the rectangle to intersect with the current clip
* @param right The right side of the rectangle to intersect with the
* current clip
* @param bottom The bottom of the rectangle to intersect with the current
* clip
* @return true if the resulting clip is non-empty
*/
public boolean clipRect(int left, int top, int right, int bottom) {
return nClipRect(mNativeCanvasWrapper, left, top, right, bottom,
Region.Op.INTERSECT.nativeInt);
}
/**
* Set the clip to the difference of the current clip and the specified rectangle, which is
* expressed in local coordinates.
*
* @param left The left side of the rectangle used in the difference operation
* @param top The top of the rectangle used in the difference operation
* @param right The right side of the rectangle used in the difference operation
* @param bottom The bottom of the rectangle used in the difference operation
* @return true if the resulting clip is non-empty
*/
public boolean clipOutRect(int left, int top, int right, int bottom) {
return nClipRect(mNativeCanvasWrapper, left, top, right, bottom,
Region.Op.DIFFERENCE.nativeInt);
}
/**
* Modify the current clip with the specified path.
*
* @param path The path to operate on the current clip
* @param op How the clip is modified
* @return true if the resulting is non-empty
*
* @deprecated Region.Op values other than {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} have the ability to expand the clip. The canvas clipping APIs
* are intended to only expand the clip as a result of a restore operation. This enables a view
* parent to clip a canvas to clearly define the maximal drawing area of its children. The
* recommended alternative calls are {@link #clipPath(Path)} and
* {@link #clipOutPath(Path)};
*
* As of API Level API level {@value Build.VERSION_CODES#P} only {@link Region.Op#INTERSECT} and
* {@link Region.Op#DIFFERENCE} are valid Region.Op parameters.
*/
@Deprecated
public boolean clipPath(@NonNull Path path, @NonNull Region.Op op) {
checkValidClipOp(op);
return nClipPath(mNativeCanvasWrapper, path.readOnlyNI(), op.nativeInt);
}
/**
* Intersect the current clip with the specified path.
*
* @param path The path to intersect with the current clip
* @return true if the resulting clip is non-empty
*/
public boolean clipPath(@NonNull Path path) {
return clipPath(path, Region.Op.INTERSECT);
}
/**
* Set the clip to the difference of the current clip and the specified path.
*
* @param path The path used in the difference operation
* @return true if the resulting clip is non-empty
*/
public boolean clipOutPath(@NonNull Path path) {
return clipPath(path, Region.Op.DIFFERENCE);
}
/**
* Modify the current clip with the specified region. Note that unlike
* clipRect() and clipPath() which transform their arguments by the
* current matrix, clipRegion() assumes its argument is already in the
* coordinate system of the current layer's bitmap, and so not
* transformation is performed.
*
* @param region The region to operate on the current clip, based on op
* @param op How the clip is modified
* @return true if the resulting is non-empty
*
* @removed
* @deprecated Unlike all other clip calls this API does not respect the
* current matrix. Use {@link #clipRect(Rect)} as an alternative.
*/
@Deprecated
public boolean clipRegion(@NonNull Region region, @NonNull Region.Op op) {
return false;
}
/**
* Intersect the current clip with the specified region. Note that unlike
* clipRect() and clipPath() which transform their arguments by the
* current matrix, clipRegion() assumes its argument is already in the
* coordinate system of the current layer's bitmap, and so not
* transformation is performed.
*
* @param region The region to operate on the current clip, based on op
* @return true if the resulting is non-empty
*
* @removed
* @deprecated Unlike all other clip calls this API does not respect the
* current matrix. Use {@link #clipRect(Rect)} as an alternative.
*/
@Deprecated
public boolean clipRegion(@NonNull Region region) {
return false;
}
public @Nullable DrawFilter getDrawFilter() {
return mDrawFilter;
}
public void setDrawFilter(@Nullable DrawFilter filter) {
long nativeFilter = 0;
if (filter != null) {
nativeFilter = filter.mNativeInt;
}
mDrawFilter = filter;
nSetDrawFilter(mNativeCanvasWrapper, nativeFilter);
}
/**
* Constant values used as parameters to {@code quickReject()} calls. These values
* specify how much space around the shape should be accounted for, depending on whether
* the shaped area is antialiased or not.
*
* @see #quickReject(float, float, float, float, EdgeType)
* @see #quickReject(Path, EdgeType)
* @see #quickReject(RectF, EdgeType)
*/
public enum EdgeType {
/**
* Black-and-White: Treat edges by just rounding to nearest pixel boundary
*/
BW(0), //!< treat edges by just rounding to nearest pixel boundary
/**
* Antialiased: Treat edges by rounding-out, since they may be antialiased
*/
AA(1);
EdgeType(int nativeInt) {
this.nativeInt = nativeInt;
}
/**
* @hide
*/
public final int nativeInt;
}
/**
* Return true if the specified rectangle, after being transformed by the
* current matrix, would lie completely outside of the current clip. Call
* this to check if an area you intend to draw into is clipped out (and
* therefore you can skip making the draw calls).
*
* @param rect the rect to compare with the current clip
* @param type {@link Canvas.EdgeType#AA} if the path should be considered antialiased,
* since that means it may affect a larger area (more pixels) than
* non-antialiased ({@link Canvas.EdgeType#BW}).
* @return true if the rect (transformed by the canvas' matrix)
* does not intersect with the canvas' clip
*/
public boolean quickReject(@NonNull RectF rect, @NonNull EdgeType type) {
return nQuickReject(mNativeCanvasWrapper,
rect.left, rect.top, rect.right, rect.bottom);
}
/**
* Return true if the specified path, after being transformed by the
* current matrix, would lie completely outside of the current clip. Call
* this to check if an area you intend to draw into is clipped out (and
* therefore you can skip making the draw calls). Note: for speed it may
* return false even if the path itself might not intersect the clip
* (i.e. the bounds of the path intersects, but the path does not).
*
* @param path The path to compare with the current clip
* @param type {@link Canvas.EdgeType#AA} if the path should be considered antialiased,
* since that means it may affect a larger area (more pixels) than
* non-antialiased ({@link Canvas.EdgeType#BW}).
* @return true if the path (transformed by the canvas' matrix)
* does not intersect with the canvas' clip
*/
public boolean quickReject(@NonNull Path path, @NonNull EdgeType type) {
return nQuickReject(mNativeCanvasWrapper, path.readOnlyNI());
}
/**
* Return true if the specified rectangle, after being transformed by the
* current matrix, would lie completely outside of the current clip. Call
* this to check if an area you intend to draw into is clipped out (and
* therefore you can skip making the draw calls).
*
* @param left The left side of the rectangle to compare with the
* current clip
* @param top The top of the rectangle to compare with the current
* clip
* @param right The right side of the rectangle to compare with the
* current clip
* @param bottom The bottom of the rectangle to compare with the
* current clip
* @param type {@link Canvas.EdgeType#AA} if the path should be considered antialiased,
* since that means it may affect a larger area (more pixels) than
* non-antialiased ({@link Canvas.EdgeType#BW}).
* @return true if the rect (transformed by the canvas' matrix)
* does not intersect with the canvas' clip
*/
public boolean quickReject(float left, float top, float right, float bottom,
@NonNull EdgeType type) {
return nQuickReject(mNativeCanvasWrapper, left, top, right, bottom);
}
/**
* Return the bounds of the current clip (in local coordinates) in the
* bounds parameter, and return true if it is non-empty. This can be useful
* in a way similar to quickReject, in that it tells you that drawing
* outside of these bounds will be clipped out.
*
* @param bounds Return the clip bounds here. If it is null, ignore it but
* still return true if the current clip is non-empty.
* @return true if the current clip is non-empty.
*/
public boolean getClipBounds(@Nullable Rect bounds) {
return nGetClipBounds(mNativeCanvasWrapper, bounds);
}
/**
* Retrieve the bounds of the current clip (in local coordinates).
*
* @return the clip bounds, or [0, 0, 0, 0] if the clip is empty.
*/
public final @NonNull Rect getClipBounds() {
Rect r = new Rect();
getClipBounds(r);
return r;
}
/**
* Save the canvas state, draw the picture, and restore the canvas state.
* This differs from picture.draw(canvas), which does not perform any
* save/restore.
*
* <p>
* <strong>Note:</strong> This forces the picture to internally call
* {@link Picture#endRecording} in order to prepare for playback.
*
* @param picture The picture to be drawn
*/
public void drawPicture(@NonNull Picture picture) {
picture.endRecording();
int restoreCount = save();
picture.draw(this);
restoreToCount(restoreCount);
}
/**
* Draw the picture, stretched to fit into the dst rectangle.
*/
public void drawPicture(@NonNull Picture picture, @NonNull RectF dst) {
save();
translate(dst.left, dst.top);
if (picture.getWidth() > 0 && picture.getHeight() > 0) {
scale(dst.width() / picture.getWidth(), dst.height() / picture.getHeight());
}
drawPicture(picture);
restore();
}
/**
* Draw the picture, stretched to fit into the dst rectangle.
*/
public void drawPicture(@NonNull Picture picture, @NonNull Rect dst) {
save();
translate(dst.left, dst.top);
if (picture.getWidth() > 0 && picture.getHeight() > 0) {
scale((float) dst.width() / picture.getWidth(),
(float) dst.height() / picture.getHeight());
}
drawPicture(picture);
restore();
}
public enum VertexMode {
TRIANGLES(0),
TRIANGLE_STRIP(1),
TRIANGLE_FAN(2);
VertexMode(int nativeInt) {
this.nativeInt = nativeInt;
}
/**
* @hide
*/
public final int nativeInt;
}
/**
* Releases the resources associated with this canvas.
*
* @hide
*/
public void release() {
mNativeCanvasWrapper = 0;
if (mFinalizer != null) {
mFinalizer.run();
mFinalizer = null;
}
}
/**
* Free up as much memory as possible from private caches (e.g. fonts, images)
*
* @hide
*/
public static void freeCaches() {
nFreeCaches();
}
/**
* Free up text layout caches
*
* @hide
*/
public static void freeTextLayoutCaches() {
nFreeTextLayoutCaches();
}
/** @hide */
public static void setCompatibilityVersion(int apiLevel) {
sCompatiblityVersion = apiLevel;
nSetCompatibilityVersion(apiLevel);
}
private static native void nFreeCaches();
private static native void nFreeTextLayoutCaches();
private static native long nInitRaster(Bitmap bitmap);
private static native long nGetNativeFinalizer();
private static native void nSetCompatibilityVersion(int apiLevel);
// ---------------- @FastNative -------------------
@FastNative
private static native void nSetBitmap(long canvasHandle, Bitmap bitmap);
@FastNative
private static native boolean nGetClipBounds(long nativeCanvas, Rect bounds);
// ---------------- @CriticalNative -------------------
@CriticalNative
private static native boolean nIsOpaque(long canvasHandle);
@CriticalNative
private static native int nGetWidth(long canvasHandle);
@CriticalNative
private static native int nGetHeight(long canvasHandle);
@CriticalNative
private static native int nSave(long canvasHandle, int saveFlags);
@CriticalNative
private static native int nSaveLayer(long nativeCanvas, float l, float t, float r, float b,
long nativePaint, int layerFlags);
@CriticalNative
private static native int nSaveLayerAlpha(long nativeCanvas, float l, float t, float r, float b,
int alpha, int layerFlags);
@CriticalNative
private static native boolean nRestore(long canvasHandle);
@CriticalNative
private static native void nRestoreToCount(long canvasHandle, int saveCount);
@CriticalNative
private static native int nGetSaveCount(long canvasHandle);
@CriticalNative
private static native void nTranslate(long canvasHandle, float dx, float dy);
@CriticalNative
private static native void nScale(long canvasHandle, float sx, float sy);
@CriticalNative
private static native void nRotate(long canvasHandle, float degrees);
@CriticalNative
private static native void nSkew(long canvasHandle, float sx, float sy);
@CriticalNative
private static native void nConcat(long nativeCanvas, long nativeMatrix);
@CriticalNative
private static native void nSetMatrix(long nativeCanvas, long nativeMatrix);
@CriticalNative
private static native boolean nClipRect(long nativeCanvas,
float left, float top, float right, float bottom, int regionOp);
@CriticalNative
private static native boolean nClipPath(long nativeCanvas, long nativePath, int regionOp);
@CriticalNative
private static native void nSetDrawFilter(long nativeCanvas, long nativeFilter);
@CriticalNative
private static native void nGetMatrix(long nativeCanvas, long nativeMatrix);
@CriticalNative
private static native boolean nQuickReject(long nativeCanvas, long nativePath);
@CriticalNative
private static native boolean nQuickReject(long nativeCanvas, float left, float top,
float right, float bottom);
// ---------------- Draw Methods -------------------
/**
* <p>
* Draw the specified arc, which will be scaled to fit inside the specified oval.
* </p>
* <p>
* If the start angle is negative or >= 360, the start angle is treated as start angle modulo
* 360.
* </p>
* <p>
* If the sweep angle is >= 360, then the oval is drawn completely. Note that this differs
* slightly from SkPath::arcTo, which treats the sweep angle modulo 360. If the sweep angle is
* negative, the sweep angle is treated as sweep angle modulo 360
* </p>
* <p>
* The arc is drawn clockwise. An angle of 0 degrees correspond to the geometric angle of 0
* degrees (3 o'clock on a watch.)
* </p>
*
* @param oval The bounds of oval used to define the shape and size of the arc
* @param startAngle Starting angle (in degrees) where the arc begins
* @param sweepAngle Sweep angle (in degrees) measured clockwise
* @param useCenter If true, include the center of the oval in the arc, and close it if it is
* being stroked. This will draw a wedge
* @param paint The paint used to draw the arc
*/
public void drawArc(@NonNull RectF oval, float startAngle, float sweepAngle, boolean useCenter,
@NonNull Paint paint) {
super.drawArc(oval, startAngle, sweepAngle, useCenter, paint);
}
/**
* <p>
* Draw the specified arc, which will be scaled to fit inside the specified oval.
* </p>
* <p>
* If the start angle is negative or >= 360, the start angle is treated as start angle modulo
* 360.
* </p>
* <p>
* If the sweep angle is >= 360, then the oval is drawn completely. Note that this differs
* slightly from SkPath::arcTo, which treats the sweep angle modulo 360. If the sweep angle is
* negative, the sweep angle is treated as sweep angle modulo 360
* </p>
* <p>
* The arc is drawn clockwise. An angle of 0 degrees correspond to the geometric angle of 0
* degrees (3 o'clock on a watch.)
* </p>
*
* @param startAngle Starting angle (in degrees) where the arc begins
* @param sweepAngle Sweep angle (in degrees) measured clockwise
* @param useCenter If true, include the center of the oval in the arc, and close it if it is
* being stroked. This will draw a wedge
* @param paint The paint used to draw the arc
*/
public void drawArc(float left, float top, float right, float bottom, float startAngle,
float sweepAngle, boolean useCenter, @NonNull Paint paint) {
super.drawArc(left, top, right, bottom, startAngle, sweepAngle, useCenter, paint);
}
/**
* Fill the entire canvas' bitmap (restricted to the current clip) with the specified ARGB
* color, using srcover porterduff mode.
*
* @param a alpha component (0..255) of the color to draw onto the canvas
* @param r red component (0..255) of the color to draw onto the canvas
* @param g green component (0..255) of the color to draw onto the canvas
* @param b blue component (0..255) of the color to draw onto the canvas
*/
public void drawARGB(int a, int r, int g, int b) {
super.drawARGB(a, r, g, b);
}
/**
* Draw the specified bitmap, with its top/left corner at (x,y), using the specified paint,
* transformed by the current matrix.
* <p>
* Note: if the paint contains a maskfilter that generates a mask which extends beyond the
* bitmap's original width/height (e.g. BlurMaskFilter), then the bitmap will be drawn as if it
* were in a Shader with CLAMP mode. Thus the color outside of the original width/height will be
* the edge color replicated.
* <p>
* If the bitmap and canvas have different densities, this function will take care of
* automatically scaling the bitmap to draw at the same density as the canvas.
*
* @param bitmap The bitmap to be drawn
* @param left The position of the left side of the bitmap being drawn
* @param top The position of the top side of the bitmap being drawn
* @param paint The paint used to draw the bitmap (may be null)
*/
public void drawBitmap(@NonNull Bitmap bitmap, float left, float top, @Nullable Paint paint) {
super.drawBitmap(bitmap, left, top, paint);
}
/**
* Draw the specified bitmap, scaling/translating automatically to fill the destination
* rectangle. If the source rectangle is not null, it specifies the subset of the bitmap to
* draw.
* <p>
* Note: if the paint contains a maskfilter that generates a mask which extends beyond the
* bitmap's original width/height (e.g. BlurMaskFilter), then the bitmap will be drawn as if it
* were in a Shader with CLAMP mode. Thus the color outside of the original width/height will be
* the edge color replicated.
* <p>
* This function <em>ignores the density associated with the bitmap</em>. This is because the
* source and destination rectangle coordinate spaces are in their respective densities, so must
* already have the appropriate scaling factor applied.
*
* @param bitmap The bitmap to be drawn
* @param src May be null. The subset of the bitmap to be drawn
* @param dst The rectangle that the bitmap will be scaled/translated to fit into
* @param paint May be null. The paint used to draw the bitmap
*/
public void drawBitmap(@NonNull Bitmap bitmap, @Nullable Rect src, @NonNull RectF dst,
@Nullable Paint paint) {
super.drawBitmap(bitmap, src, dst, paint);
}
/**
* Draw the specified bitmap, scaling/translating automatically to fill the destination
* rectangle. If the source rectangle is not null, it specifies the subset of the bitmap to
* draw.
* <p>
* Note: if the paint contains a maskfilter that generates a mask which extends beyond the
* bitmap's original width/height (e.g. BlurMaskFilter), then the bitmap will be drawn as if it
* were in a Shader with CLAMP mode. Thus the color outside of the original width/height will be
* the edge color replicated.
* <p>
* This function <em>ignores the density associated with the bitmap</em>. This is because the
* source and destination rectangle coordinate spaces are in their respective densities, so must
* already have the appropriate scaling factor applied.
*
* @param bitmap The bitmap to be drawn
* @param src May be null. The subset of the bitmap to be drawn
* @param dst The rectangle that the bitmap will be scaled/translated to fit into
* @param paint May be null. The paint used to draw the bitmap
*/
public void drawBitmap(@NonNull Bitmap bitmap, @Nullable Rect src, @NonNull Rect dst,
@Nullable Paint paint) {
super.drawBitmap(bitmap, src, dst, paint);
}
/**
* Treat the specified array of colors as a bitmap, and draw it. This gives the same result as
* first creating a bitmap from the array, and then drawing it, but this method avoids
* explicitly creating a bitmap object which can be more efficient if the colors are changing
* often.
*
* @param colors Array of colors representing the pixels of the bitmap
* @param offset Offset into the array of colors for the first pixel
* @param stride The number of colors in the array between rows (must be >= width or <= -width).
* @param x The X coordinate for where to draw the bitmap
* @param y The Y coordinate for where to draw the bitmap
* @param width The width of the bitmap
* @param height The height of the bitmap
* @param hasAlpha True if the alpha channel of the colors contains valid values. If false, the
* alpha byte is ignored (assumed to be 0xFF for every pixel).
* @param paint May be null. The paint used to draw the bitmap
* @deprecated Usage with a {@link #isHardwareAccelerated() hardware accelerated} canvas
* requires an internal copy of color buffer contents every time this method is
* called. Using a Bitmap avoids this copy, and allows the application to more
* explicitly control the lifetime and copies of pixel data.
*/
@Deprecated
public void drawBitmap(@NonNull int[] colors, int offset, int stride, float x, float y,
int width, int height, boolean hasAlpha, @Nullable Paint paint) {
super.drawBitmap(colors, offset, stride, x, y, width, height, hasAlpha, paint);
}
/**
* Legacy version of drawBitmap(int[] colors, ...) that took ints for x,y
*
* @deprecated Usage with a {@link #isHardwareAccelerated() hardware accelerated} canvas
* requires an internal copy of color buffer contents every time this method is
* called. Using a Bitmap avoids this copy, and allows the application to more
* explicitly control the lifetime and copies of pixel data.
*/
@Deprecated
public void drawBitmap(@NonNull int[] colors, int offset, int stride, int x, int y,
int width, int height, boolean hasAlpha, @Nullable Paint paint) {
super.drawBitmap(colors, offset, stride, x, y, width, height, hasAlpha, paint);
}
/**
* Draw the bitmap using the specified matrix.
*
* @param bitmap The bitmap to draw
* @param matrix The matrix used to transform the bitmap when it is drawn
* @param paint May be null. The paint used to draw the bitmap
*/
public void drawBitmap(@NonNull Bitmap bitmap, @NonNull Matrix matrix, @Nullable Paint paint) {
super.drawBitmap(bitmap, matrix, paint);
}
/**
* Draw the bitmap through the mesh, where mesh vertices are evenly distributed across the
* bitmap. There are meshWidth+1 vertices across, and meshHeight+1 vertices down. The verts
* array is accessed in row-major order, so that the first meshWidth+1 vertices are distributed
* across the top of the bitmap from left to right. A more general version of this method is
* drawVertices().
*
* Prior to API level {@value Build.VERSION_CODES#P} vertOffset and colorOffset were ignored,
* effectively treating them as zeros. In API level {@value Build.VERSION_CODES#P} and above
* these parameters will be respected.
*
* @param bitmap The bitmap to draw using the mesh
* @param meshWidth The number of columns in the mesh. Nothing is drawn if this is 0
* @param meshHeight The number of rows in the mesh. Nothing is drawn if this is 0
* @param verts Array of x,y pairs, specifying where the mesh should be drawn. There must be at
* least (meshWidth+1) * (meshHeight+1) * 2 + vertOffset values in the array
* @param vertOffset Number of verts elements to skip before drawing
* @param colors May be null. Specifies a color at each vertex, which is interpolated across the
* cell, and whose values are multiplied by the corresponding bitmap colors. If not
* null, there must be at least (meshWidth+1) * (meshHeight+1) + colorOffset values
* in the array.
* @param colorOffset Number of color elements to skip before drawing
* @param paint May be null. The paint used to draw the bitmap
*/
public void drawBitmapMesh(@NonNull Bitmap bitmap, int meshWidth, int meshHeight,
@NonNull float[] verts, int vertOffset, @Nullable int[] colors, int colorOffset,
@Nullable Paint paint) {
super.drawBitmapMesh(bitmap, meshWidth, meshHeight, verts, vertOffset, colors, colorOffset,
paint);
}
/**
* Draw the specified circle using the specified paint. If radius is <= 0, then nothing will be
* drawn. The circle will be filled or framed based on the Style in the paint.
*
* @param cx The x-coordinate of the center of the cirle to be drawn
* @param cy The y-coordinate of the center of the cirle to be drawn
* @param radius The radius of the cirle to be drawn
* @param paint The paint used to draw the circle
*/
public void drawCircle(float cx, float cy, float radius, @NonNull Paint paint) {
super.drawCircle(cx, cy, radius, paint);
}
/**
* Fill the entire canvas' bitmap (restricted to the current clip) with the specified color,
* using srcover porterduff mode.
*
* @param color the color to draw onto the canvas
*/
public void drawColor(@ColorInt int color) {
super.drawColor(color);
}
/**
* Fill the entire canvas' bitmap (restricted to the current clip) with the specified color and
* porter-duff xfermode.
*
* @param color the color to draw with
* @param mode the porter-duff mode to apply to the color
*/
public void drawColor(@ColorInt int color, @NonNull PorterDuff.Mode mode) {
super.drawColor(color, mode);
}
/**
* Draw a line segment with the specified start and stop x,y coordinates, using the specified
* paint.
* <p>
* Note that since a line is always "framed", the Style is ignored in the paint.
* </p>
* <p>
* Degenerate lines (length is 0) will not be drawn.
* </p>
*
* @param startX The x-coordinate of the start point of the line
* @param startY The y-coordinate of the start point of the line
* @param paint The paint used to draw the line
*/
public void drawLine(float startX, float startY, float stopX, float stopY,
@NonNull Paint paint) {
super.drawLine(startX, startY, stopX, stopY, paint);
}
/**
* Draw a series of lines. Each line is taken from 4 consecutive values in the pts array. Thus
* to draw 1 line, the array must contain at least 4 values. This is logically the same as
* drawing the array as follows: drawLine(pts[0], pts[1], pts[2], pts[3]) followed by
* drawLine(pts[4], pts[5], pts[6], pts[7]) and so on.
*
* @param pts Array of points to draw [x0 y0 x1 y1 x2 y2 ...]
* @param offset Number of values in the array to skip before drawing.
* @param count The number of values in the array to process, after skipping "offset" of them.
* Since each line uses 4 values, the number of "lines" that are drawn is really
* (count >> 2).
* @param paint The paint used to draw the points
*/
public void drawLines(@Size(multiple = 4) @NonNull float[] pts, int offset, int count,
@NonNull Paint paint) {
super.drawLines(pts, offset, count, paint);
}
public void drawLines(@Size(multiple = 4) @NonNull float[] pts, @NonNull Paint paint) {
super.drawLines(pts, paint);
}
/**
* Draw the specified oval using the specified paint. The oval will be filled or framed based on
* the Style in the paint.
*
* @param oval The rectangle bounds of the oval to be drawn
*/
public void drawOval(@NonNull RectF oval, @NonNull Paint paint) {
super.drawOval(oval, paint);
}
/**
* Draw the specified oval using the specified paint. The oval will be filled or framed based on
* the Style in the paint.
*/
public void drawOval(float left, float top, float right, float bottom, @NonNull Paint paint) {
super.drawOval(left, top, right, bottom, paint);
}
/**
* Fill the entire canvas' bitmap (restricted to the current clip) with the specified paint.
* This is equivalent (but faster) to drawing an infinitely large rectangle with the specified
* paint.
*
* @param paint The paint used to draw onto the canvas
*/
public void drawPaint(@NonNull Paint paint) {
super.drawPaint(paint);
}
/**
* Draws the specified bitmap as an N-patch (most often, a 9-patches.)
*
* @param patch The ninepatch object to render
* @param dst The destination rectangle.
* @param paint The paint to draw the bitmap with. may be null
* @hide
*/
public void drawPatch(@NonNull NinePatch patch, @NonNull Rect dst, @Nullable Paint paint) {
super.drawPatch(patch, dst, paint);
}
/**
* Draws the specified bitmap as an N-patch (most often, a 9-patches.)
*
* @param patch The ninepatch object to render
* @param dst The destination rectangle.
* @param paint The paint to draw the bitmap with. may be null
* @hide
*/
public void drawPatch(@NonNull NinePatch patch, @NonNull RectF dst, @Nullable Paint paint) {
super.drawPatch(patch, dst, paint);
}
/**
* Draw the specified path using the specified paint. The path will be filled or framed based on
* the Style in the paint.
*
* @param path The path to be drawn
* @param paint The paint used to draw the path
*/
public void drawPath(@NonNull Path path, @NonNull Paint paint) {
super.drawPath(path, paint);
}
/**
* Helper for drawPoints() for drawing a single point.
*/
public void drawPoint(float x, float y, @NonNull Paint paint) {
super.drawPoint(x, y, paint);
}
/**
* Draw a series of points. Each point is centered at the coordinate specified by pts[], and its
* diameter is specified by the paint's stroke width (as transformed by the canvas' CTM), with
* special treatment for a stroke width of 0, which always draws exactly 1 pixel (or at most 4
* if antialiasing is enabled). The shape of the point is controlled by the paint's Cap type.
* The shape is a square, unless the cap type is Round, in which case the shape is a circle.
*
* @param pts Array of points to draw [x0 y0 x1 y1 x2 y2 ...]
* @param offset Number of values to skip before starting to draw.
* @param count The number of values to process, after skipping offset of them. Since one point
* uses two values, the number of "points" that are drawn is really (count >> 1).
* @param paint The paint used to draw the points
*/
public void drawPoints(@Size(multiple = 2) float[] pts, int offset, int count,
@NonNull Paint paint) {
super.drawPoints(pts, offset, count, paint);
}
/**
* Helper for drawPoints() that assumes you want to draw the entire array
*/
public void drawPoints(@Size(multiple = 2) @NonNull float[] pts, @NonNull Paint paint) {
super.drawPoints(pts, paint);
}
/**
* Draw the text in the array, with each character's origin specified by the pos array.
*
* @param text The text to be drawn
* @param index The index of the first character to draw
* @param count The number of characters to draw, starting from index.
* @param pos Array of [x,y] positions, used to position each character
* @param paint The paint used for the text (e.g. color, size, style)
* @deprecated This method does not support glyph composition and decomposition and should
* therefore not be used to render complex scripts. It also doesn't handle
* supplementary characters (eg emoji).
*/
@Deprecated
public void drawPosText(@NonNull char[] text, int index, int count,
@NonNull @Size(multiple = 2) float[] pos,
@NonNull Paint paint) {
super.drawPosText(text, index, count, pos, paint);
}
/**
* Draw the text in the array, with each character's origin specified by the pos array.
*
* @param text The text to be drawn
* @param pos Array of [x,y] positions, used to position each character
* @param paint The paint used for the text (e.g. color, size, style)
* @deprecated This method does not support glyph composition and decomposition and should
* therefore not be used to render complex scripts. It also doesn't handle
* supplementary characters (eg emoji).
*/
@Deprecated
public void drawPosText(@NonNull String text, @NonNull @Size(multiple = 2) float[] pos,
@NonNull Paint paint) {
super.drawPosText(text, pos, paint);
}
/**
* Draw the specified Rect using the specified paint. The rectangle will be filled or framed
* based on the Style in the paint.
*
* @param rect The rect to be drawn
* @param paint The paint used to draw the rect
*/
public void drawRect(@NonNull RectF rect, @NonNull Paint paint) {
super.drawRect(rect, paint);
}
/**
* Draw the specified Rect using the specified Paint. The rectangle will be filled or framed
* based on the Style in the paint.
*
* @param r The rectangle to be drawn.
* @param paint The paint used to draw the rectangle
*/
public void drawRect(@NonNull Rect r, @NonNull Paint paint) {
super.drawRect(r, paint);
}
/**
* Draw the specified Rect using the specified paint. The rectangle will be filled or framed
* based on the Style in the paint.
*
* @param left The left side of the rectangle to be drawn
* @param top The top side of the rectangle to be drawn
* @param right The right side of the rectangle to be drawn
* @param bottom The bottom side of the rectangle to be drawn
* @param paint The paint used to draw the rect
*/
public void drawRect(float left, float top, float right, float bottom, @NonNull Paint paint) {
super.drawRect(left, top, right, bottom, paint);
}
/**
* Fill the entire canvas' bitmap (restricted to the current clip) with the specified RGB color,
* using srcover porterduff mode.
*
* @param r red component (0..255) of the color to draw onto the canvas
* @param g green component (0..255) of the color to draw onto the canvas
* @param b blue component (0..255) of the color to draw onto the canvas
*/
public void drawRGB(int r, int g, int b) {
super.drawRGB(r, g, b);
}
/**
* Draw the specified round-rect using the specified paint. The roundrect will be filled or
* framed based on the Style in the paint.
*
* @param rect The rectangular bounds of the roundRect to be drawn
* @param rx The x-radius of the oval used to round the corners
* @param ry The y-radius of the oval used to round the corners
* @param paint The paint used to draw the roundRect
*/
public void drawRoundRect(@NonNull RectF rect, float rx, float ry, @NonNull Paint paint) {
super.drawRoundRect(rect, rx, ry, paint);
}
/**
* Draw the specified round-rect using the specified paint. The roundrect will be filled or
* framed based on the Style in the paint.
*
* @param rx The x-radius of the oval used to round the corners
* @param ry The y-radius of the oval used to round the corners
* @param paint The paint used to draw the roundRect
*/
public void drawRoundRect(float left, float top, float right, float bottom, float rx, float ry,
@NonNull Paint paint) {
super.drawRoundRect(left, top, right, bottom, rx, ry, paint);
}
/**
* Draw the text, with origin at (x,y), using the specified paint. The origin is interpreted
* based on the Align setting in the paint.
*
* @param text The text to be drawn
* @param x The x-coordinate of the origin of the text being drawn
* @param y The y-coordinate of the baseline of the text being drawn
* @param paint The paint used for the text (e.g. color, size, style)
*/
public void drawText(@NonNull char[] text, int index, int count, float x, float y,
@NonNull Paint paint) {
super.drawText(text, index, count, x, y, paint);
}
/**
* Draw the text, with origin at (x,y), using the specified paint. The origin is interpreted
* based on the Align setting in the paint.
*
* @param text The text to be drawn
* @param x The x-coordinate of the origin of the text being drawn
* @param y The y-coordinate of the baseline of the text being drawn
* @param paint The paint used for the text (e.g. color, size, style)
*/
public void drawText(@NonNull String text, float x, float y, @NonNull Paint paint) {
super.drawText(text, x, y, paint);
}
/**
* Draw the text, with origin at (x,y), using the specified paint. The origin is interpreted
* based on the Align setting in the paint.
*
* @param text The text to be drawn
* @param start The index of the first character in text to draw
* @param end (end - 1) is the index of the last character in text to draw
* @param x The x-coordinate of the origin of the text being drawn
* @param y The y-coordinate of the baseline of the text being drawn
* @param paint The paint used for the text (e.g. color, size, style)
*/
public void drawText(@NonNull String text, int start, int end, float x, float y,
@NonNull Paint paint) {
super.drawText(text, start, end, x, y, paint);
}
/**
* Draw the specified range of text, specified by start/end, with its origin at (x,y), in the
* specified Paint. The origin is interpreted based on the Align setting in the Paint.
*
* @param text The text to be drawn
* @param start The index of the first character in text to draw
* @param end (end - 1) is the index of the last character in text to draw
* @param x The x-coordinate of origin for where to draw the text
* @param y The y-coordinate of origin for where to draw the text
* @param paint The paint used for the text (e.g. color, size, style)
*/
public void drawText(@NonNull CharSequence text, int start, int end, float x, float y,
@NonNull Paint paint) {
super.drawText(text, start, end, x, y, paint);
}
/**
* Draw the text, with origin at (x,y), using the specified paint, along the specified path. The
* paint's Align setting determins where along the path to start the text.
*
* @param text The text to be drawn
* @param path The path the text should follow for its baseline
* @param hOffset The distance along the path to add to the text's starting position
* @param vOffset The distance above(-) or below(+) the path to position the text
* @param paint The paint used for the text (e.g. color, size, style)
*/
public void drawTextOnPath(@NonNull char[] text, int index, int count, @NonNull Path path,
float hOffset, float vOffset, @NonNull Paint paint) {
super.drawTextOnPath(text, index, count, path, hOffset, vOffset, paint);
}
/**
* Draw the text, with origin at (x,y), using the specified paint, along the specified path. The
* paint's Align setting determins where along the path to start the text.
*
* @param text The text to be drawn
* @param path The path the text should follow for its baseline
* @param hOffset The distance along the path to add to the text's starting position
* @param vOffset The distance above(-) or below(+) the path to position the text
* @param paint The paint used for the text (e.g. color, size, style)
*/
public void drawTextOnPath(@NonNull String text, @NonNull Path path, float hOffset,
float vOffset, @NonNull Paint paint) {
super.drawTextOnPath(text, path, hOffset, vOffset, paint);
}
/**
* Draw a run of text, all in a single direction, with optional context for complex text
* shaping.
* <p>
* See {@link #drawTextRun(CharSequence, int, int, int, int, float, float, boolean, Paint)} for
* more details. This method uses a character array rather than CharSequence to represent the
* string. Also, to be consistent with the pattern established in {@link #drawText}, in this
* method {@code count} and {@code contextCount} are used rather than offsets of the end
* position; {@code count = end - start, contextCount = contextEnd -
* contextStart}.
*
* @param text the text to render
* @param index the start of the text to render
* @param count the count of chars to render
* @param contextIndex the start of the context for shaping. Must be no greater than index.
* @param contextCount the number of characters in the context for shaping. contexIndex +
* contextCount must be no less than index + count.
* @param x the x position at which to draw the text
* @param y the y position at which to draw the text
* @param isRtl whether the run is in RTL direction
* @param paint the paint
*/
public void drawTextRun(@NonNull char[] text, int index, int count, int contextIndex,
int contextCount, float x, float y, boolean isRtl, @NonNull Paint paint) {
super.drawTextRun(text, index, count, contextIndex, contextCount, x, y, isRtl, paint);
}
/**
* Draw a run of text, all in a single direction, with optional context for complex text
* shaping.
* <p>
* The run of text includes the characters from {@code start} to {@code end} in the text. In
* addition, the range {@code contextStart} to {@code contextEnd} is used as context for the
* purpose of complex text shaping, such as Arabic text potentially shaped differently based on
* the text next to it.
* <p>
* All text outside the range {@code contextStart..contextEnd} is ignored. The text between
* {@code start} and {@code end} will be laid out and drawn.
* <p>
* The direction of the run is explicitly specified by {@code isRtl}. Thus, this method is
* suitable only for runs of a single direction. Alignment of the text is as determined by the
* Paint's TextAlign value. Further, {@code 0 <= contextStart <= start <= end <= contextEnd
* <= text.length} must hold on entry.
* <p>
* Also see {@link android.graphics.Paint#getRunAdvance} for a corresponding method to measure
* the text; the advance width of the text drawn matches the value obtained from that method.
*
* @param text the text to render
* @param start the start of the text to render. Data before this position can be used for
* shaping context.
* @param end the end of the text to render. Data at or after this position can be used for
* shaping context.
* @param contextStart the index of the start of the shaping context
* @param contextEnd the index of the end of the shaping context
* @param x the x position at which to draw the text
* @param y the y position at which to draw the text
* @param isRtl whether the run is in RTL direction
* @param paint the paint
* @see #drawTextRun(char[], int, int, int, int, float, float, boolean, Paint)
*/
public void drawTextRun(@NonNull CharSequence text, int start, int end, int contextStart,
int contextEnd, float x, float y, boolean isRtl, @NonNull Paint paint) {
super.drawTextRun(text, start, end, contextStart, contextEnd, x, y, isRtl, paint);
}
/**
* Draw the array of vertices, interpreted as triangles (based on mode). The verts array is
* required, and specifies the x,y pairs for each vertex. If texs is non-null, then it is used
* to specify the coordinate in shader coordinates to use at each vertex (the paint must have a
* shader in this case). If there is no texs array, but there is a color array, then each color
* is interpolated across its corresponding triangle in a gradient. If both texs and colors
* arrays are present, then they behave as before, but the resulting color at each pixels is the
* result of multiplying the colors from the shader and the color-gradient together. The indices
* array is optional, but if it is present, then it is used to specify the index of each
* triangle, rather than just walking through the arrays in order.
*
* @param mode How to interpret the array of vertices
* @param vertexCount The number of values in the vertices array (and corresponding texs and
* colors arrays if non-null). Each logical vertex is two values (x, y), vertexCount
* must be a multiple of 2.
* @param verts Array of vertices for the mesh
* @param vertOffset Number of values in the verts to skip before drawing.
* @param texs May be null. If not null, specifies the coordinates to sample into the current
* shader (e.g. bitmap tile or gradient)
* @param texOffset Number of values in texs to skip before drawing.
* @param colors May be null. If not null, specifies a color for each vertex, to be interpolated
* across the triangle.
* @param colorOffset Number of values in colors to skip before drawing.
* @param indices If not null, array of indices to reference into the vertex (texs, colors)
* array.
* @param indexCount number of entries in the indices array (if not null).
* @param paint Specifies the shader to use if the texs array is non-null.
*/
public void drawVertices(@NonNull VertexMode mode, int vertexCount, @NonNull float[] verts,
int vertOffset, @Nullable float[] texs, int texOffset, @Nullable int[] colors,
int colorOffset, @Nullable short[] indices, int indexOffset, int indexCount,
@NonNull Paint paint) {
super.drawVertices(mode, vertexCount, verts, vertOffset, texs, texOffset,
colors, colorOffset, indices, indexOffset, indexCount, paint);
}
}
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