Add slide widget

src/components/SlideWidget.cpp

@@ -0,0 +1,61 @@
+#include "SlideWidget.h"
+#include <QScrollBar>
+#include <QMouseEvent>
+#include <QApplication>
+#include <qdebug.h>
+
+
+SlideWidget::SlideWidget(QWidget* parent):
+QWidget(parent)
+, mIsDragging(false)
+, mOriginPosY(-1)
+, mOriginScrollBarV(0)
+{
+}
+
+SlideWidget::~SlideWidget()
+{
+}
+
+void SlideWidget::setVerticalScrollBar(QScrollBar* bar)
+{
+    if (!bar) return;
+    mVerticalScrollBar = bar;
+}
+
+void SlideWidget::mousePressEvent(QMouseEvent* ev)
+{
+    mIsDragging = true;
+    mOriginPosY = ev->globalPos().y();
+    mOriginScrollBarV = this->verticalScrollBar()->value();
+    QWidget::mousePressEvent(ev);
+}
+
+void SlideWidget::mouseMoveEvent(QMouseEvent* ev)
+{
+    if (!mIsDragging) {
+        QWidget::mouseMoveEvent(ev);
+        return;
+    }
+    if (this->verticalScrollBar()->isVisible()) {
+        int offset = mOriginPosY - ev->globalPos().y();
+        int nv = offset+mOriginScrollBarV;
+        int max = this->verticalScrollBar()->maximum();
+        int min = this->verticalScrollBar()->minimum();
+        nv = nv > max ? max : (nv < min ? min : nv);
+
+        this->verticalScrollBar()->setValue(nv);
+    }
+    QWidget::mouseMoveEvent(ev);
+}
+
+void SlideWidget::mouseReleaseEvent(QMouseEvent* ev)
+{
+    if (!mIsDragging)mIsDragging = false;
+    QWidget::mouseReleaseEvent(ev);
+}
+
+QScrollBar* SlideWidget::verticalScrollBar()
+{
+    return mVerticalScrollBar;
+}

src/components/SlideWidget.h

@@ -0,0 +1,23 @@
+#ifndef GUI_SLIDEWIDGET_H
+#define GUI_SLIDEWIDGET_H
+
+#include <QWidget>
+class QScrollBar;
+class SlideWidget: public QWidget {
+Q_OBJECT
+public:
+    explicit SlideWidget(QWidget *parent = nullptr);
+    ~SlideWidget() override;
+    void setVerticalScrollBar(QScrollBar* bar);
+protected:
+    void mousePressEvent(QMouseEvent *ev) override ;
+    void mouseMoveEvent(QMouseEvent *ev) override ;
+    void mouseReleaseEvent(QMouseEvent *ev) override ;
+    QScrollBar* verticalScrollBar();
+private:
+    bool mIsDragging;
+    int mdirect = 0;
+    int mOriginPosY,mOriginScrollBarV;
+    QScrollBar* mVerticalScrollBar;
+};
+#endif //GUI_SLIDEWIDGET_H