chore: no longer based on QMainWindow

Since most of the features that QMainWindow offered will never be
used in this program. We don't need a statusbar, a menubar, etc.

CMakeLists.txt

@@ -28,6 +28,7 @@ endif ()
 #LibExiv2_FOUND
 set (PPIC_CPP_FILES
     app/main.cpp
+    app/framelesswindow.cpp
     app/mainwindow.cpp
     app/graphicsview.cpp
     app/graphicsscene.cpp
@@ -44,6 +45,7 @@ set (PPIC_CPP_FILES
 )
 
 set (PPIC_HEADER_FILES
+    app/framelesswindow.h
     app/mainwindow.h
     app/graphicsview.h
     app/graphicsscene.h

app/framelesswindow.cpp

@@ -0,0 +1,23 @@
+#include "framelesswindow.h"
+
+#include <QVBoxLayout>
+
+FramelessWindow::FramelessWindow(QWidget *parent)
+    : QWidget(parent)
+    , m_centralLayout(new QVBoxLayout(this))
+{
+    this->setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowMinimizeButtonHint);
+
+    m_centralLayout->setMargin(0);
+}
+
+void FramelessWindow::setCentralWidget(QWidget *widget)
+{
+    if (m_centralWidget) {
+        m_centralLayout->removeWidget(m_centralWidget);
+        m_centralWidget->deleteLater();
+    }
+
+    m_centralLayout->addWidget(widget);
+    m_centralWidget = widget;
+}

app/framelesswindow.h

@@ -0,0 +1,25 @@
+#ifndef FRAMELESSWINDOW_H
+#define FRAMELESSWINDOW_H
+
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+class QVBoxLayout;
+QT_END_NAMESPACE
+
+class FramelessWindow : public QWidget
+{
+    Q_OBJECT
+public:
+    explicit FramelessWindow(QWidget *parent = nullptr);
+
+    void setCentralWidget(QWidget * widget);
+
+signals:
+
+private:
+    QVBoxLayout * m_centralLayout = nullptr;
+    QWidget * m_centralWidget = nullptr; // just a pointer, doesn't take the ownership.
+};
+
+#endif // FRAMELESSWINDOW_H

app/mainwindow.cpp

@@ -31,12 +31,10 @@
 #endif // _WIN32
 
 MainWindow::MainWindow(QWidget *parent) :
-    QMainWindow(parent)
+    FramelessWindow(parent)
 {
     if (Settings::instance()->stayOnTop()) {
-        this->setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowMinimizeButtonHint | Qt::WindowStaysOnTopHint);
-    } else {
-        this->setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowMinimizeButtonHint);
+        this->setWindowFlag(Qt::WindowStaysOnTopHint);
     }
 
     this->setAttribute(Qt::WA_TranslucentBackground, true);
@@ -55,7 +53,7 @@ MainWindow::MainWindow(QWidget *parent) :
     m_exitAnimationGroup->addAnimation(m_fadeOutAnimation);
     m_exitAnimationGroup->addAnimation(m_floatUpAnimation);
     connect(m_exitAnimationGroup, &QParallelAnimationGroup::finished,
-            this, &QMainWindow::close);
+            this, &QWidget::close);
 
     GraphicsScene * scene = new GraphicsScene(this);
 
@@ -290,7 +288,7 @@ void MainWindow::showEvent(QShowEvent *event)
 {
     updateWidgetsPosition();
 
-    return QMainWindow::showEvent(event);
+    return FramelessWindow::showEvent(event);
 }
 
 void MainWindow::enterEvent(QEvent *event)
@@ -302,7 +300,7 @@ void MainWindow::enterEvent(QEvent *event)
     m_prevButton->setOpacity(1);
     m_nextButton->setOpacity(1);
 
-    return QMainWindow::enterEvent(event);
+    return FramelessWindow::enterEvent(event);
 }
 
 void MainWindow::leaveEvent(QEvent *event)
@@ -314,7 +312,7 @@ void MainWindow::leaveEvent(QEvent *event)
     m_prevButton->setOpacity(0);
     m_nextButton->setOpacity(0);
 
-    return QMainWindow::leaveEvent(event);
+    return FramelessWindow::leaveEvent(event);
 }
 
 void MainWindow::mousePressEvent(QMouseEvent *event)
@@ -327,7 +325,7 @@ void MainWindow::mousePressEvent(QMouseEvent *event)
         event->accept();
     }
 
-    return QMainWindow::mousePressEvent(event);
+    return FramelessWindow::mousePressEvent(event);
 }
 
 void MainWindow::mouseMoveEvent(QMouseEvent *event)
@@ -343,14 +341,14 @@ void MainWindow::mouseMoveEvent(QMouseEvent *event)
         event->accept();
     }
 
-    return QMainWindow::mouseMoveEvent(event);
+    return FramelessWindow::mouseMoveEvent(event);
 }
 
 void MainWindow::mouseReleaseEvent(QMouseEvent *event)
 {
     m_clickedOnWindow = false;
 
-    return QMainWindow::mouseReleaseEvent(event);
+    return FramelessWindow::mouseReleaseEvent(event);
 }
 
 void MainWindow::mouseDoubleClickEvent(QMouseEvent *event)
@@ -391,7 +389,7 @@ void MainWindow::wheelEvent(QWheelEvent *event)
         m_graphicsView->zoomView(zoomIn ? 1.25 : 0.8);
         event->accept();
     } else {
-        QMainWindow::wheelEvent(event);
+        FramelessWindow::wheelEvent(event);
     }
 }
 
@@ -399,7 +397,7 @@ void MainWindow::resizeEvent(QResizeEvent *event)
 {
     updateWidgetsPosition();
 
-    return QMainWindow::resizeEvent(event);
+    return FramelessWindow::resizeEvent(event);
 }
 
 void MainWindow::contextMenuEvent(QContextMenuEvent *event)
@@ -514,7 +512,7 @@ void MainWindow::contextMenuEvent(QContextMenuEvent *event)
     menu->exec(mapToGlobal(event->pos()));
     menu->deleteLater();
 
-    return QMainWindow::contextMenuEvent(event);
+    return FramelessWindow::contextMenuEvent(event);
 }
 
 bool MainWindow::nativeEvent(const QByteArray &eventType, void *message, long *result)
@@ -600,7 +598,7 @@ bool MainWindow::nativeEvent(const QByteArray &eventType, void *message, long *r
 
     return false;
 #else
-    return QMainWindow::nativeEvent(eventType, message, result);
+    return FramelessWindow::nativeEvent(eventType, message, result);
 #endif // _WIN32
 }
 

app/mainwindow.h

@@ -1,7 +1,8 @@
 #ifndef MAINWINDOW_H
 #define MAINWINDOW_H
 
-#include <QMainWindow>
+#include "framelesswindow.h"
+
 #include <QParallelAnimationGroup>
 #include <QPropertyAnimation>
 #include <QPushButton>
@@ -15,7 +16,7 @@ class ToolButton;
 class GraphicsView;
 class NavigatorView;
 class BottomButtonGroup;
-class MainWindow : public QMainWindow
+class MainWindow : public FramelessWindow
 {
     Q_OBJECT