OBS 源窗口 自定义SourceListWidget 列表分析

前面分析了源窗口 信号槽的关联 及触发机制

下面这篇文章主要分析下UI层 自定义的源列表

 

 

1  首先，看看添加场景项的函数代码

void OBSBasic::AddSceneItem(OBSSceneItem item)
{
	obs_scene_t  *scene  = obs_sceneitem_get_scene(item);

	if (GetCurrentScene() == scene)
		InsertSceneItem(item);

	SaveProject();

	/*
	obs_source_t *sceneSource = obs_scene_get_source(scene);    //场景 源
	obs_source_t *itemSource = obs_sceneitem_get_source(item);  //场景中的 子项 源

	QString name1= obs_source_get_name(itemSource); //视频捕获设备
	QString name2 = obs_source_get_id(itemSource);   //dshow_input
	QString name3 = obs_source_get_name(sceneSource);//场景

	blog(LOG_INFO, "User added source '%s' (%s) to scene '%s'",
		obs_source_get_name(itemSource),
		obs_source_get_id(itemSource),
		obs_source_get_name(sceneSource));
	*/


	if (!disableSaving) {
		obs_source_t *sceneSource = obs_scene_get_source(scene);
		obs_source_t *itemSource = obs_sceneitem_get_source(item);
		blog(LOG_INFO, "User added source '%s' (%s) to scene '%s'",
				obs_source_get_name(itemSource),
				obs_source_get_id(itemSource),
				obs_source_get_name(sceneSource));
	}
}

 

 

其中，重要的是 如果是属于当前场景的场景项，则将其插入到源列表中

    obs_scene_t  *scene  = obs_sceneitem_get_scene(item);

    if (GetCurrentScene() == scene)
        InsertSceneItem(item);

 

void OBSBasic::InsertSceneItem(obs_sceneitem_t *item)
{
	QListWidgetItem *listItem = new QListWidgetItem();
	SetOBSRef(listItem, OBSSceneItem(item));

	ui->sources->insertItem(0, listItem);
	ui->sources->setCurrentRow(0, QItemSelectionModel::ClearAndSelect);

	SetupVisibilityItem(ui->sources, listItem, item);
}

 

QListWidgetItem *listItem = new QListWidgetItem();  新创建列表项目

template <typename T>
static void SetOBSRef(QListWidgetItem *item, T &&val)
{
    item->setData(static_cast<int>(QtDataRole::OBSRef),
            QVariant::fromValue(val));
}
SetOBSRef(listItem, OBSSceneItem(item));   //将列表项data关联场景项

 

    ui->sources->insertItem(0, listItem);    //插入到列表项中
    ui->sources->setCurrentRow(0, QItemSelectionModel::ClearAndSelect);

 

SetupVisibilityItem(ui->sources, listItem, item);  //安装可见性ITem  这是重点

看看这个是怎么实现的

 

2 设置列表项 自定义widget

void SetupVisibilityItem(QListWidget *list, QListWidgetItem *item,
        obs_sceneitem_t *sceneItem)
{
    VisibilityItemWidget *baseWidget = new VisibilityItemWidget(sceneItem);

    item->setSizeHint(baseWidget->sizeHint());
    list->setItemWidget(item, baseWidget);
}

这里，通过list->setItermWidget 将子项设置为一个自定义的widget

下面看看这个自定义的widget如何定义的

 

#pragma once

#include <QWidget>
#include <QStyledItemDelegate>
#include <obs.hpp>

class QLabel;
class QLineEdit;
class QListWidget;
class QListWidgetItem;
class VisibilityCheckBox;
class LockedCheckBox;

class VisibilityItemWidget : public QWidget {
	Q_OBJECT

private:
	OBSSceneItem item;
	OBSSource source;
	QLabel *label = nullptr;
	VisibilityCheckBox *vis = nullptr;
	LockedCheckBox *lock = nullptr;
	QString oldName;

	OBSSignal sceneRemoveSignal;
	OBSSignal enabledSignal;
	OBSSignal renamedSignal;
	bool sceneRemoved = false;

	bool active = false;
	bool selected = false;

	static void OBSSceneRemove(void *param, calldata_t *data);
	static void OBSSceneItemRemove(void *param, calldata_t *data);
	static void OBSSceneItemVisible(void *param, calldata_t *data);
	static void OBSSceneItemLocked(void *param, calldata_t *data);
	static void OBSSourceEnabled(void *param, calldata_t *data);
	static void OBSSourceRenamed(void *param, calldata_t *data);

	void DisconnectItemSignals();

private slots:
	void VisibilityClicked(bool visible);
	void LockClicked(bool locked);
	void SourceEnabled(bool enabled);
	void SourceRenamed(QString name);
	void SourceLocked(bool locked);

public:
	VisibilityItemWidget(obs_source_t *source);
	VisibilityItemWidget(obs_sceneitem_t *item);
	~VisibilityItemWidget();

	void SetColor(const QColor &color, bool active, bool selected);


public://...by yujian
	QString GetName();

};

class VisibilityItemDelegate : public QStyledItemDelegate {
	Q_OBJECT

public:
	VisibilityItemDelegate(QObject *parent = nullptr);

	void paint(QPainter *painter, const QStyleOptionViewItem &option,
			const QModelIndex &index) const override;
};

void SetupVisibilityItem(QListWidget *list, QListWidgetItem *item,
		obs_source_t *source);
void SetupVisibilityItem(QListWidget *list, QListWidgetItem *item,
		obs_sceneitem_t *sceneItem);

 

看看其构造函数

VisibilityItemWidget::VisibilityItemWidget(obs_sceneitem_t *item_)
	: item          (item_),
	  source        (obs_sceneitem_get_source(item)),
	  renamedSignal (obs_source_get_signal_handler(source), "rename",
	                 OBSSourceRenamed, this)
{
	const char *name = obs_source_get_name(source);
	bool enabled = obs_sceneitem_visible(item);
	bool locked = obs_sceneitem_locked(item);
	obs_scene_t *scene = obs_sceneitem_get_scene(item);
	obs_source_t *sceneSource = obs_scene_get_source(scene);

	vis = new VisibilityCheckBox();
	vis->setSizePolicy(QSizePolicy::Maximum, QSizePolicy::Maximum);
	/* Fix for non-apple systems where the spacing would be too big */
#ifndef __APPLE__
	vis->setMaximumSize(16, 16);
#endif
	vis->setChecked(enabled);

	lock = new LockedCheckBox();
	lock->setSizePolicy(QSizePolicy::Maximum, QSizePolicy::Maximum);
	/* Fix for non-apple systems where the spacing would be too big */
#ifndef __APPLE__
	lock->setMaximumSize(16, 16);
#endif
	lock->setChecked(locked);

	label = new QLabel(QT_UTF8(name));
	label->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);

#ifdef __APPLE__
	vis->setAttribute(Qt::WA_LayoutUsesWidgetRect);
	lock->setAttribute(Qt::WA_LayoutUsesWidgetRect);
#endif

	QHBoxLayout *itemLayout = new QHBoxLayout();
	itemLayout->addWidget(vis);
	itemLayout->addWidget(lock);
	itemLayout->addWidget(label);
	itemLayout->setContentsMargins(5, 2, 5, 2);
	itemLayout->setSpacing(2);

	setLayout(itemLayout);
	setStyleSheet("background-color: rgba(255, 255, 255, 0);");

	signal_handler_t *signal = obs_source_get_signal_handler(sceneSource);
	signal_handler_connect(signal, "remove", OBSSceneRemove, this);
	signal_handler_connect(signal, "item_remove", OBSSceneItemRemove,
			this);
	signal_handler_connect(signal, "item_visible", OBSSceneItemVisible,
			this);

	connect(vis, SIGNAL(clicked(bool)),
			this, SLOT(VisibilityClicked(bool)));

	connect(lock, SIGNAL(clicked(bool)),
			this, SLOT(LockClicked(bool)));
}

分析下，这个构造函数

在VisibilityItemWidget(obs_sceneitem_t *item_)构造函数中，

vis = new VisibilityCheckBox();

lock = new LockedCheckBox();

构造了两个自定义的checkbox，对应于源的 眼睛和锁checkbox按钮

然后又定义了一个LABEL

label = new QLabel(QT_UTF8(name));

随后，将其放入水平布局中

    QHBoxLayout *itemLayout = new QHBoxLayout();
    itemLayout->addWidget(vis);
    itemLayout->addWidget(lock);
    itemLayout->addWidget(label);
    itemLayout->setContentsMargins(5, 2, 5, 2);
    itemLayout->setSpacing(2);
 

    setLayout(itemLayout);                                                            // 设置整个widget布局为水平布局
    setStyleSheet("background-color: rgba(255, 255, 255, 0);");  // 设置widget样式

 

下面，设置widget项对应的一些信号处理

    signal_handler_t *signal = obs_source_get_signal_handler(sceneSource);
    signal_handler_connect(signal, "remove", OBSSceneRemove, this);
    signal_handler_connect(signal, "item_remove", OBSSceneItemRemove,
            this);
    signal_handler_connect(signal, "item_visible", OBSSceneItemVisible,
            this);

在libobs中 进行移除等操作时，会同时发出响应信息，进行UI层列表项的处理

比如：LIBOBS中 场景项的删除，会发出item_remove信号，从而UI层同步删除列表中对应的子项

static inline void signal_item_remove(struct obs_scene_item *item)
{
    struct calldata params;
    uint8_t stack[128];

    calldata_init_fixed(&params, stack, sizeof(stack));
    calldata_set_ptr(&params, "scene", item->parent);
    calldata_set_ptr(&params, "item", item);

    signal_handler_signal(item->parent->source->context.signals,
            "item_remove", &params);
}
 

最后，是关联两个checkbox的点击信号

    connect(vis, SIGNAL(clicked(bool)),
            this, SLOT(VisibilityClicked(bool)));

    connect(lock, SIGNAL(clicked(bool)),
            this, SLOT(LockClicked(bool)));

 

3 自定义checbox的实现

 

#include <QCheckBox>
#include <QPixmap>

class QPaintEvernt;

class VisibilityCheckBox : public QCheckBox {
	Q_OBJECT

	QPixmap checkedImage;
	QPixmap uncheckedImage;

public:
	VisibilityCheckBox();

protected:
	void paintEvent(QPaintEvent *event) override;
};

 

#include <QPaintEvent>
#include <QPixmap>
#include <QPainter>
#include "visibility-checkbox.hpp"

#include <util/c99defs.h>

VisibilityCheckBox::VisibilityCheckBox() : QCheckBox()
{
	checkedImage =
		QPixmap::fromImage(QImage(":/res/images/visible_mask.png"));
	uncheckedImage =
		QPixmap::fromImage(QImage(":/res/images/invisible_mask.png"));
	setMinimumSize(16, 16);

	setStyleSheet("outline: none;");
}

void VisibilityCheckBox::paintEvent(QPaintEvent *event)
{
	UNUSED_PARAMETER(event);

	QPixmap &pixmap = isChecked() ? checkedImage : uncheckedImage;
	QImage image(pixmap.size(), QImage::Format_ARGB32);

	QPainter draw(&image);
	draw.setCompositionMode(QPainter::CompositionMode_Source);
	draw.drawPixmap(0, 0, pixmap.width(), pixmap.height(), pixmap);
	draw.setCompositionMode(QPainter::CompositionMode_SourceIn);
	draw.fillRect(QRectF(QPointF(0.0f, 0.0f), pixmap.size()),
			palette().color(foregroundRole()));

	QPainter p(this);
	p.drawPixmap(0, 0, image.width(), image.height(),
			QPixmap::fromImage(image));
}

 

4 获得源列表项中自定义widget的相关信息，比如源名字信息

 

 

比如，遍历源

	for (int i = 0; i < ui->sources->count(); i++) {
		QListWidgetItem *listItem = ui->sources->item(i);
  
        
		QWidget* pDisplayWidget = ui->sources->itemWidget(listItem);
		VisibilityItemWidget* pOBSItemWidget = (VisibilityItemWidget*)pDisplayWidget;
		QString itemName = pOBSItemWidget->GetName();
        //QString itemText = listItem->text();  //空，因为列表项关联的是widget

		if (GetOBSRef<OBSSceneItem>(listItem) == item) {


            obs_scene_t *scene = obs_sceneitem_get_scene(item);
            obs_source_t *sceneSource = obs_scene_get_source(scene);
            obs_source_t *itemSource = obs_sceneitem_get_source(item);

            obs_source_get_name(itemSource);
            obs_source_get_id(itemSource);
            obs_source_get_name(sceneSource);

			DeleteListItem(ui->sources, listItem);

			break;

		}
	}