Fixed a bug with body redrawing and added some documentation

src/gui/widgets/timeline-widget.cpp

@@ -110,7 +110,8 @@ TimelineWidget::set_time_offset(gavl_time_t time_offset)
   
   timeOffset = time_offset;
   horizontalAdjustment.set_value(time_offset);
-  ruler->update_view();
+  
+  viewChangedSignal.emit();
 }
 
 int64_t
@@ -129,7 +130,7 @@ TimelineWidget::set_time_scale(int64_t time_scale)
   const int view_width = body->get_allocation().get_width();
   horizontalAdjustment.set_page_size(timeScale * view_width);
   
-  ruler->update_view();
+  viewChangedSignal.emit();
 }
 
 void
@@ -261,6 +262,12 @@ TimelineWidget::set_tool(ToolType tool_type)
   body->set_tool(tool_type);
 }
 
+sigc::signal<void>
+TimelineWidget::view_changed_signal() const
+{
+  return viewChangedSignal;
+}
+
 sigc::signal<void, gavl_time_t>
 TimelineWidget::mouse_hover_signal() const
 {
@@ -271,7 +278,7 @@ void
 TimelineWidget::on_scroll()
 {
   timeOffset = horizontalAdjustment.get_value();
-  ruler->update_view();
+  viewChangedSignal.emit();
 }
   
 void

src/gui/widgets/timeline-widget.hpp

@@ -157,6 +157,8 @@ public:
   
 public:
   /* ===== Signals ===== */
+  sigc::signal<void> view_changed_signal() const;
+  
   sigc::signal<void, gavl_time_t> mouse_hover_signal() const;
     
   /* ===== Events ===== */
@@ -208,10 +210,17 @@ protected:
   Gtk::HScrollbar horizontalScroll;
   Gtk::VScrollbar verticalScroll;
   
+  // Signals
+  sigc::signal<void> viewChangedSignal;
   sigc::signal<void, gavl_time_t> mouseHoverSignal;
    
   /* ===== Constants ===== */
 public:
+  /**
+   * The maximum scale for timeline display.
+   * @remarks At MaxScale, every pixel on the timeline is equivalent
+   * to 30000000 gavl_time_t increments.
+   */ 
   static const int64_t MaxScale;
   
 protected:

src/gui/widgets/timeline/timeline-body.cpp

@@ -55,10 +55,8 @@ TimelineBody::TimelineBody(lumiera::gui::widgets::TimelineWidget
   REQUIRE(timelineWidget != NULL);
       
   // Connect up some events  
-  timelineWidget->horizontalAdjustment.signal_value_changed().connect(
-    sigc::mem_fun(this, &TimelineBody::on_scroll) );
-  timelineWidget->verticalAdjustment.signal_value_changed().connect(
-    sigc::mem_fun(this, &TimelineBody::on_scroll) );
+  timelineWidget->view_changed_signal().connect(sigc::mem_fun(
+    this, &TimelineBody::on_update_view) );
   
   // Install style properties
   register_styles();
@@ -109,6 +107,12 @@ TimelineBody::set_tool(timeline::ToolType tool_type)
   tool->apply_cursor();
 }
 
+void
+TimelineBody::on_update_view()
+{
+  queue_draw();
+}
+
 void
 TimelineBody::on_realize()
 {
@@ -217,12 +221,6 @@ TimelineBody::on_expose_event(GdkEventExpose* event)
   
   return true;
 }
-
-void
-TimelineBody::on_scroll()
-{
-  queue_draw();
-}
   
 bool
 TimelineBody::on_scroll_event (GdkEventScroll* event)

src/gui/widgets/timeline/timeline-body.hpp

@@ -52,6 +52,9 @@ public:
    */
   TimelineBody(lumiera::gui::widgets::TimelineWidget *timeline_widget);
   
+  /**
+   * Destructor
+   */
   ~TimelineBody();
   
   /**
@@ -68,6 +71,11 @@ public:
   /* ===== Events ===== */
 protected:
 
+  /**
+   * An event handler for when the view window of the timeline changes.
+   */
+  void on_update_view();
+
   /**
    * An event handler for when the widget is realized.
    */
@@ -77,8 +85,6 @@ protected:
    * An event handler for when the window must be redrawn.
    */
   bool on_expose_event(GdkEventExpose* event);
-
-  void on_scroll();
   
   bool on_scroll_event(GdkEventScroll* event);
   

src/gui/widgets/timeline/timeline-ruler.cpp

@@ -63,6 +63,10 @@ TimelineRuler::TimelineRuler(
 {
   REQUIRE(timelineWidget != NULL);
   
+  // Connect event handlers
+  timelineWidget->view_changed_signal().connect(sigc::mem_fun(
+    this, &TimelineRuler::on_update_view) );
+  
   // Install style properties
   register_styles();
 }
@@ -75,7 +79,7 @@ TimelineRuler::set_mouse_chevron_offset(int offset)
 }
 
 void
-TimelineRuler::update_view()
+TimelineRuler::on_update_view()
 {
   rulerImage.clear();
   queue_draw();
@@ -222,8 +226,8 @@ TimelineRuler::draw_ruler(Cairo::RefPtr<Cairo::Context> cr,
   REQUIRE(ruler_rect.get_height() > 0);
   REQUIRE(timelineWidget != NULL);
   
-  const gavl_time_t left_offset = timelineWidget->timeOffset;
-  const int64_t time_scale = timelineWidget->timeScale;
+  const gavl_time_t left_offset = timelineWidget->get_time_offset();
+  const int64_t time_scale = timelineWidget->get_time_scale();
   
   // Preparation steps
   const int height = ruler_rect.get_height();

src/gui/widgets/timeline/timeline-ruler.hpp

@@ -59,14 +59,14 @@ public:
    */
   void set_mouse_chevron_offset(int offset);
   
-  /**
-   * Causes the ruler to be redrawn from scratch. The cached ruler
-   * backdrop is destroyed and redrawn.
-   */
-  void update_view();
-
   /* ===== Events ===== */
-protected:
+private:
+  /**
+   * An event handler for when the view window of the timeline changes.
+   * @remarks Causes the ruler to be redrawn from scratch. The cached
+   * ruler backdrop is destroyed and redrawn.
+   */
+  void on_update_view();
 
   /**
    * An event handler for when the widget is realized.