Add minimal Qt desktop pet window

src/ui/PetWindow.cpp

@@ -0,0 +1,141 @@
+#include "PetWindow.h"
+
+#include <QAction>
+#include <QContextMenuEvent>
+#include <QCursor>
+#include <QFileInfo>
+#include <QGuiApplication>
+#include <QMenu>
+#include <QMouseEvent>
+#include <QPixmap>
+#include <QScreen>
+#include <QVBoxLayout>
+
+namespace
+{
+QString previewImagePath()
+{
+    return QStringLiteral(PET_SOURCE_DIR) + QStringLiteral("/shiroko/preview.png");
+}
+}
+
+PetWindow::PetWindow(QWidget *parent)
+    : QWidget(parent)
+    , m_imageLabel(new QLabel(this))
+    , m_dragging(false)
+    , m_alwaysOnTop(true)
+{
+    setAttribute(Qt::WA_TranslucentBackground);
+    setWindowFlags(Qt::FramelessWindowHint | Qt::Tool | Qt::WindowStaysOnTopHint);
+    setMouseTracking(true);
+
+    m_imageLabel->setAlignment(Qt::AlignCenter);
+    m_imageLabel->setAttribute(Qt::WA_TranslucentBackground);
+
+    auto *layout = new QVBoxLayout(this);
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->addWidget(m_imageLabel);
+
+    loadPreviewImage();
+}
+
+void PetWindow::contextMenuEvent(QContextMenuEvent *event)
+{
+    QMenu menu(this);
+
+    QAction *topAction = menu.addAction(QStringLiteral("取消置顶"));
+    topAction->setCheckable(true);
+    topAction->setChecked(m_alwaysOnTop);
+
+    menu.addSeparator();
+    QAction *exitAction = menu.addAction(QStringLiteral("退出"));
+
+    QAction *selectedAction = menu.exec(event->globalPos());
+    if (selectedAction == topAction)
+    {
+        setAlwaysOnTop(!m_alwaysOnTop);
+    }
+    else if (selectedAction == exitAction)
+    {
+        close();
+    }
+}
+
+void PetWindow::mouseMoveEvent(QMouseEvent *event)
+{
+    if (m_dragging && (event->buttons() & Qt::LeftButton))
+    {
+        move(event->globalPosition().toPoint() - m_dragOffset);
+        event->accept();
+        return;
+    }
+
+    QWidget::mouseMoveEvent(event);
+}
+
+void PetWindow::mousePressEvent(QMouseEvent *event)
+{
+    if (event->button() == Qt::LeftButton)
+    {
+        m_dragging = true;
+        m_dragOffset = event->globalPosition().toPoint() - frameGeometry().topLeft();
+        event->accept();
+        return;
+    }
+
+    QWidget::mousePressEvent(event);
+}
+
+void PetWindow::mouseReleaseEvent(QMouseEvent *event)
+{
+    if (event->button() == Qt::LeftButton)
+    {
+        m_dragging = false;
+        event->accept();
+        return;
+    }
+
+    QWidget::mouseReleaseEvent(event);
+}
+
+void PetWindow::loadPreviewImage()
+{
+    const QString imagePath = previewImagePath();
+    QPixmap pixmap(imagePath);
+    if (pixmap.isNull())
+    {
+        m_imageLabel->setText(QStringLiteral("QtDesktopPet"));
+        resize(240, 160);
+        return;
+    }
+
+    const QSize targetSize(320, 320);
+    const QPixmap scaled = pixmap.scaled(targetSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+    m_imageLabel->setPixmap(scaled);
+    resize(scaled.size());
+
+    if (const QScreen *screen = QGuiApplication::primaryScreen())
+    {
+        const QRect available = screen->availableGeometry();
+        move(available.center() - rect().center());
+    }
+}
+
+void PetWindow::setAlwaysOnTop(bool enabled)
+{
+    m_alwaysOnTop = enabled;
+
+    Qt::WindowFlags flags = windowFlags();
+    if (enabled)
+    {
+        flags |= Qt::WindowStaysOnTopHint;
+    }
+    else
+    {
+        flags &= ~Qt::WindowStaysOnTopHint;
+    }
+
+    setWindowFlags(flags);
+    show();
+}
+