cabana: sync play button state (#26917)

sync play button

tools/cabana/canmessages.cc

@@ -91,6 +91,11 @@ void CANMessages::seekTo(double ts) {
   emit updated();
 }
 
+void CANMessages::pause(bool pause) { 
+  replay->pause(pause); 
+  emit (pause ? paused() : resume());
+}
+
 void CANMessages::settingChanged() {
   replay->setSegmentCacheLimit(settings.cached_segment_limit);
 }

tools/cabana/canmessages.h

@@ -38,10 +38,12 @@ public:
   inline const std::vector<Event *> *events() const { return replay->events(); }
   inline void setSpeed(float speed) { replay->setSpeed(speed); }
   inline bool isPaused() const { return replay->isPaused(); }
-  inline void pause(bool pause) { replay->pause(pause); }
+  void pause(bool pause);
   inline const std::vector<std::tuple<int, int, TimelineType>> getTimeline() { return replay->getTimeline(); }
 
 signals:
+  void paused();
+  void resume();
   void seekedTo(double sec);
   void streamStarted();
   void eventsMerged();

tools/cabana/videowidget.cc

@@ -63,22 +63,19 @@ VideoWidget::VideoWidget(QWidget *parent) : QFrame(parent) {
   }
   main_layout->addLayout(control_layout);
 
-  QObject::connect(can, &CANMessages::updated, this, &VideoWidget::updateState);
   QObject::connect(slider, &QSlider::sliderReleased, [this]() { can->seekTo(slider->value() / 1000.0); });
   QObject::connect(slider, &QSlider::valueChanged, [=](int value) { time_label->setText(formatTime(value / 1000)); });
-  QObject::connect(cam_widget, &CameraWidget::clicked, [this]() { pause(!can->isPaused()); });
-  QObject::connect(play_btn, &QPushButton::clicked, [=]() { pause(!can->isPaused()); });
+  QObject::connect(cam_widget, &CameraWidget::clicked, []() { can->pause(!can->isPaused()); });
+  QObject::connect(play_btn, &QPushButton::clicked, []() { can->pause(!can->isPaused()); });
+  QObject::connect(can, &CANMessages::updated, this, &VideoWidget::updateState);
+  QObject::connect(can, &CANMessages::paused, [this]() { play_btn->setText("▶"); });
+  QObject::connect(can, &CANMessages::resume, [this]() { play_btn->setText("⏸"); });
   QObject::connect(can, &CANMessages::streamStarted, [this]() {
     end_time_label->setText(formatTime(can->totalSeconds()));
     slider->setRange(0, can->totalSeconds() * 1000);
   });
 }
 
-void VideoWidget::pause(bool pause) {
-  play_btn->setText(!pause ? "⏸" : "▶");
-  can->pause(pause);
-}
-
 void VideoWidget::rangeChanged(double min, double max, bool is_zoomed) {
   if (!is_zoomed) {
     min = 0;

tools/cabana/videowidget.h

@@ -44,7 +44,6 @@ public:
 
 protected:
   void updateState();
-  void pause(bool pause);
 
   CameraWidget *cam_widget;
   QLabel *end_time_label;