新功能：完成QTransformDemo部分功能

    1、打印部分输出信息；
    2、实现滑动条控制平移原点功能。

PaintingDemo/TransformDemo/renderarea.cpp

 #include "renderarea.h"
-
+#include <QDebug>
 #include <qpainter.h>
 
 RenderArea::RenderArea(QWidget *parent) : QWidget(parent)
@@ -8,6 +8,7 @@ RenderArea::RenderArea(QWidget *parent) : QWidget(parent)
     this->setBackgroundRole(QPalette::Base);
     this->setAutoFillBackground(true);
 
+    showData();
 }
 
 RenderArea::~RenderArea()
@@ -22,9 +23,27 @@ RenderArea::~RenderArea()
 void RenderArea::setTransform(const QTransform &transform)
 {
     m_transform = transform;
+    showData();
     this->update();
 }
 
+void RenderArea::showData()
+{
+    qDebug() << "-----------------------打印信息-----------------------";
+    qDebug() << "矩阵元素：" << QString("[%1, %2, %3][%4, %5, %6][%7, %8, %9]")
+                .arg(m_transform.m11()).arg(m_transform.m12()).arg(m_transform.m13())    // 水平缩放、垂直剪切、水平投影
+                .arg(m_transform.m21()).arg(m_transform.m22()).arg(m_transform.m23())    // 水平剪切、垂直缩放、垂直投影
+                .arg(m_transform.m31()).arg(m_transform.m32()).arg(m_transform.m33());   // 水平平移、垂直平移、投影因子
+    qDebug() << "转换类型：" << m_transform.type();
+    qDebug() << "仿射变换：" << m_transform.isAffine();
+    qDebug() << "单位矩阵（TxNone）：" << m_transform.isIdentity();
+    qDebug() << "矩阵可逆：" << m_transform.isInvertible();
+    qDebug() << "矩阵旋转：" << m_transform.isRotating();
+    qDebug() << "矩阵缩放：" << m_transform.isScaling();
+    qDebug() << "矩阵偏移：" << m_transform.isTranslating();
+
+}
+
 
 void RenderArea::paintEvent(QPaintEvent *event)
 {

PaintingDemo/TransformDemo/renderarea.h

@@ -12,7 +12,8 @@ public:
 
     void setTransform(const QTransform &transform);
 
-signals:
+private:
+    void showData();
 
 protected:
     void paintEvent(QPaintEvent *event) override;

PaintingDemo/TransformDemo/widget.cpp

 #include "widget.h"
 #include "ui_widget.h"
+#include <QDebug>
 
 Widget::Widget(QWidget *parent)
     : QWidget(parent)
@@ -7,10 +8,11 @@ Widget::Widget(QWidget *parent)
 {
     ui->setupUi(this);
 
-    m_transform.translate(50, 50);
-    m_transform.rotate(10);
-    m_transform.scale(1, 1.0);
+//    m_transform.translate(50, 50);
+//    m_transform.rotate(10);
+//    m_transform.scale(0.5, 1);
 
+    ui->renderArea->installEventFilter(this);
 }
 
 Widget::~Widget()
@@ -19,17 +21,70 @@ Widget::~Widget()
 }
 
 /**
- * @brief          获取反转副本
- * @param checked
+ * @brief            事件过滤器
+ * @param watched
+ * @param event
+ * @return
  */
-void Widget::on_checkBox_transform_clicked(bool checked)
+bool Widget::eventFilter(QObject *watched, QEvent *event)
 {
-    if(checked)
+    if(watched == ui->renderArea && event->type() == QEvent::Resize)
     {
-        ui->renderArea->setTransform(m_transform.inverted());
-    }
-    else
-    {
-        ui->renderArea->setTransform(m_transform);
+        ui->horizontalSlider_origin->setMaximum(ui->renderArea->width());
+        ui->verticalSlider_origin->setMaximum(ui->renderArea->height());
+
+        ui->horizontalSlider_origin->setValue(0);
+        ui->verticalSlider_origin->setValue(ui->renderArea->height());
     }
+
+    return  QWidget::eventFilter(watched, event);
+}
+
+/**
+ * @brief 设置原始变换
+ */
+void Widget::on_but_original_clicked()
+{
+    ui->renderArea->setTransform(m_transform);
+}
+
+/**
+ * @brief  重置QTransform
+ */
+void Widget::on_but_reset_clicked()
+{
+    m_transform.reset();
+    ui->renderArea->setTransform(m_transform);
+}
+
+/**
+ * @brief 获取反转副本
+ */
+void Widget::on_but_transform_clicked()
+{
+    ui->renderArea->setTransform(m_transform.inverted());
+}
+
+/**
+ * @brief        水平偏移原点
+ * @param value
+ */
+void Widget::on_horizontalSlider_origin_valueChanged(int value)
+{
+    static int pastValue = 0;
+    m_transform.translate(value - pastValue,  0);           // 由于QTransform设置时累加的，所以这里需要通过pastValue计算差值
+    pastValue = value;
+    ui->renderArea->setTransform(m_transform);
+}
+
+/**
+ * @brief        垂直偏移原点
+ * @param value
+ */
+void Widget::on_verticalSlider_origin_valueChanged(int value)
+{
+    static int pastValue = 0;
+    m_transform.translate(0, ui->verticalSlider_origin->maximum() - value - pastValue);
+    pastValue = ui->verticalSlider_origin->maximum() - value;
+    ui->renderArea->setTransform(m_transform);
 }

PaintingDemo/TransformDemo/widget.h

@@ -15,8 +15,20 @@ public:
     Widget(QWidget *parent = nullptr);
     ~Widget();
 
+protected:
+    bool eventFilter(QObject *watched, QEvent *event) override;
+
 private slots:
-    void on_checkBox_transform_clicked(bool checked);
+
+    void on_but_reset_clicked();
+
+    void on_but_transform_clicked();
+
+    void on_but_original_clicked();
+
+    void on_horizontalSlider_origin_valueChanged(int value);
+
+    void on_verticalSlider_origin_valueChanged(int value);
 
 private:
     Ui::Widget *ui;

PaintingDemo/TransformDemo/widget.ui

@@ -14,40 +14,53 @@
    <string>Widget</string>
   </property>
   <layout class="QGridLayout" name="gridLayout">
-   <item row="2" column="1">
-    <widget class="QSlider" name="horizontalSlider_2">
-     <property name="orientation">
-      <enum>Qt::Horizontal</enum>
-     </property>
-    </widget>
-   </item>
-   <item row="2" column="3">
-    <widget class="QDial" name="dial"/>
-   </item>
    <item row="1" column="1" colspan="3">
     <widget class="RenderArea" name="renderArea" native="true"/>
    </item>
    <item row="1" column="0">
-    <widget class="QSlider" name="verticalSlider">
+    <widget class="QSlider" name="verticalSlider_origin">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
      </property>
+     <property name="tickPosition">
+      <enum>QSlider::TicksBelow</enum>
+     </property>
+    </widget>
+   </item>
+   <item row="5" column="2">
+    <widget class="QPushButton" name="but_reset">
+     <property name="text">
+      <string>重置</string>
+     </property>
+    </widget>
+   </item>
+   <item row="4" column="2">
+    <widget class="QPushButton" name="but_transform">
+     <property name="text">
+      <string>反转</string>
+     </property>
     </widget>
    </item>
    <item row="0" column="1" colspan="3">
-    <widget class="QSlider" name="horizontalSlider">
+    <widget class="QSlider" name="horizontalSlider_origin">
      <property name="orientation">
       <enum>Qt::Horizontal</enum>
      </property>
+     <property name="tickPosition">
+      <enum>QSlider::TicksBelow</enum>
+     </property>
     </widget>
    </item>
-   <item row="2" column="2">
-    <widget class="QCheckBox" name="checkBox_transform">
+   <item row="3" column="2">
+    <widget class="QPushButton" name="but_original">
      <property name="text">
-      <string>反转Transform</string>
+      <string>原始</string>
      </property>
     </widget>
    </item>
+   <item row="2" column="3" rowspan="4">
+    <widget class="QDial" name="dial"/>
+   </item>
   </layout>
  </widget>
  <customwidgets>