[feature/qt6_media_viewer] Add focus indicator

Author: AriKHaji

plugins/media_viewer/include/media_viewer/media_viewer.h

@@ -116,13 +116,19 @@ namespace hal
         /** @brief Stop playback and fully unload the current media. */
         void handleStopTriggered();
 
+        /** @brief Track focus transitions to drive the keyboard-focus indicator. */
+        void handleFocusChanged(QWidget* old, QWidget* now);
+
     private:
         /** @brief Return the tooltip text listing all keyboard shortcuts. */
         static QString shortcutHelpText();
 
         /** @brief Stop playback, detach the media source, and reset all load-derived visual state. */
         void clearMedia();
 
+        /** @brief Draw the keyboard-focus outline when this widget (or a descendant) has focus. */
+        void paintEvent(QPaintEvent* event) override;
+
         /** @brief Clamp the current volume by delta into [0,100] and update slider + audio output. */
         void adjustVolume(int delta);
 
@@ -166,5 +172,6 @@ namespace hal
         bool           mUpdatingSlider    = false;
         bool           mMuted             = false;
         bool           mSeekingFirstFrame = false;  // true while auto-playing to decode frame 0
+        bool           mHasFocusWithin    = false;
     };
 }    // namespace hal

plugins/media_viewer/src/media_viewer.cpp

@@ -30,6 +30,7 @@
 #include "hal_core/utilities/log.h"
 
 #include <QAction>
+#include <QApplication>
 #include <QAudioOutput>
 #include <QComboBox>
 #include <QCursor>
@@ -38,6 +39,8 @@
 #include <QHBoxLayout>
 #include <QLabel>
 #include <QMediaPlayer>
+#include <QPaintEvent>
+#include <QPainter>
 #include <QShortcut>
 #include <QSizePolicy>
 #include <QSlider>
@@ -163,6 +166,7 @@ namespace hal
         // ---------------------------------------------------------------
         // Assemble content layout
         // ---------------------------------------------------------------
+        mContentLayout->setContentsMargins(2, 2, 2, 2);
         mContentLayout->addWidget(mDisplayStack, 1);
         mContentLayout->addWidget(controlBar, 0);
 
@@ -218,6 +222,7 @@ namespace hal
         connect(mPlayer, &QMediaPlayer::durationChanged,      this, &MediaViewer::handleDurationChanged);
         connect(mPlayer, &QMediaPlayer::errorOccurred,        this, &MediaViewer::handleMediaError);
         connect(mPlayer, &QMediaPlayer::sourceChanged,        this, &MediaViewer::handleSourceChanged);
+        connect(qApp,    &QApplication::focusChanged,         this, &MediaViewer::handleFocusChanged);
     }
 
     MediaViewer::~MediaViewer() = default;
@@ -432,6 +437,28 @@ namespace hal
         mStopAction->setEnabled(!source.isEmpty());
     }
 
+    void MediaViewer::handleFocusChanged(QWidget* /*old*/, QWidget* now)
+    {
+        bool wantFocus = (now != nullptr) && isAncestorOf(now);
+        if (wantFocus != mHasFocusWithin)
+        {
+            mHasFocusWithin = wantFocus;
+            update();
+        }
+    }
+
+    void MediaViewer::paintEvent(QPaintEvent* event)
+    {
+        ExternalContentWidget::paintEvent(event);
+        if (!mHasFocusWithin)
+            return;
+        QPainter painter(this);
+        painter.setRenderHint(QPainter::Antialiasing);
+        painter.setBrush(Qt::NoBrush);
+        painter.setPen(QPen(QColor(40, 200, 240), 1));
+        painter.drawRect(rect().adjusted(1, 1, -1, -1));
+    }
+
     void MediaViewer::handleStopTriggered()
     {
         log_info("media_viewer", "Stopped and unloaded.");