pstats: Add Alt+Left in GTK flame graph to go back

See #1658

pandatool/src/gtk-stats/gtkStatsFlameGraph.cxx

@@ -161,7 +161,7 @@ set_time_units(int unit_mask) {
  */
 void GtkStatsFlameGraph::
 on_click_label(int collector_index) {
-  set_collector_index(collector_index);
+  push_collector_index(collector_index);
 }
 
 /**
@@ -440,7 +440,7 @@ handle_button_press(int graph_x, int graph_y, bool double_click, int button) {
             g_signal_connect(G_OBJECT(menu_item), "activate",
               G_CALLBACK(+[] (GtkWidget *widget, gpointer data) {
                 GtkStatsFlameGraph *self = (GtkStatsFlameGraph *)data;
-                self->set_collector_index(self->_popup_index);
+                self->push_collector_index(self->_popup_index);
               }),
               this);
           }
@@ -508,7 +508,13 @@ handle_button_press(int graph_x, int graph_y, bool double_click, int button) {
     else if (double_click && button == 1) {
       // Double-clicking on a color bar in the graph will zoom the graph into
       // that collector.
-      set_collector_index(collector_index);
+      if (collector_index >= 0) {
+        push_collector_index(collector_index);
+      } else {
+        // Double-clicking the background goes to the top.
+        clear_history();
+        set_collector_index(-1);
+      }
       return TRUE;
     }
   }
@@ -772,19 +778,29 @@ key_press_callback(GtkWidget *widget, GdkEventKey *event, gpointer data) {
   bool changed = false;
   switch (event->keyval) {
   case GDK_KEY_Left:
-    changed = self->prev_frame();
+    if (event->state & GDK_MOD1_MASK) {
+      changed = self->pop_collector_index();
+    } else {
+      changed = self->prev_frame();
+    }
     break;
 
   case GDK_KEY_Right:
-    changed = self->next_frame();
+    if ((event->state & GDK_MOD1_MASK) == 0) {
+      changed = self->next_frame();
+    }
     break;
 
   case GDK_KEY_Home:
-    changed = self->first_frame();
+    if ((event->state & GDK_MOD1_MASK) == 0) {
+      changed = self->first_frame();
+    }
     break;
 
   case GDK_KEY_End:
-    changed = self->last_frame();
+    if ((event->state & GDK_MOD1_MASK) == 0) {
+      changed = self->last_frame();
+    }
     break;
   }
 

pandatool/src/mac-stats/macStatsFlameGraph.h

@@ -84,8 +84,6 @@ private:
   NSToolbarItem *_total_item;
 
   MacStatsChartMenuDelegate *_menu_delegate;
-
-  std::vector<int> _back_stack;
 };
 
 #endif

pandatool/src/mac-stats/macStatsFlameGraph.mm

@@ -177,11 +177,10 @@ void MacStatsFlameGraph::
 on_click_label(int collector_index) {
   int current = get_collector_index();
   if (collector_index != current) {
-    if (_back_stack.empty()) {
+    if (get_history_depth() == 0) {
       _graph_view_controller.backToolbarItemVisible = YES;
     }
-    _back_stack.push_back(current);
-    set_collector_index(collector_index);
+    push_collector_index(collector_index);
 
     std::string window_title = get_title_text();
     if (!is_title_unknown()) {
@@ -589,11 +588,12 @@ handle_button_press(int graph_x, int graph_y, bool double_click, int button) {
       if (collector_index >= 0) {
         on_click_label(collector_index);
       } else {
-        if (!_back_stack.empty()) {
-          _back_stack.clear();
+        if (get_history_depth() > 0) {
+          clear_history();
           _graph_view_controller.backToolbarItemVisible = NO;
         }
         set_collector_index(-1);
+
         std::string window_title = get_title_text();
         if (!is_title_unknown()) {
           _window.title = [NSString stringWithUTF8String:window_title.c_str()];
@@ -726,12 +726,8 @@ handle_draw_graph(CGContextRef ctx, NSRect rect) {
  */
 void MacStatsFlameGraph::
 handle_back() {
-  if (!_back_stack.empty()) {
-    int collector_index = _back_stack.back();
-    _back_stack.pop_back();
-    set_collector_index(collector_index);
-
-    if (_back_stack.empty()) {
+  if (pop_collector_index()) {
+    if (get_history_depth() == 0) {
       _graph_view_controller.backToolbarItemVisible = NO;
     }
 

pandatool/src/pstatserver/pStatFlameGraph.I

@@ -27,6 +27,22 @@ get_collector_index() const {
   return _collector_index;
 }
 
+/**
+ * Clears the history stack.
+ */
+INLINE void PStatFlameGraph::
+clear_history() {
+  _history.clear();
+}
+
+/**
+ * Returns the depth of the history stack.
+ */
+INLINE size_t PStatFlameGraph::
+get_history_depth() const {
+  return _history.size();
+}
+
 /**
  * Returns the particular frame number whose data this flame graph reflects.
  * Returns -1 if we're looking at a moving average instead.

pandatool/src/pstatserver/pStatFlameGraph.cxx

@@ -98,6 +98,8 @@ update() {
 /**
  * Changes the collector represented by this flame graph.  This may force a
  * redraw.
+ *
+ * Leaves the history stack untouched.
  */
 void PStatFlameGraph::
 set_collector_index(int collector_index) {
@@ -127,6 +129,32 @@ set_collector_index(int collector_index) {
   }
 }
 
+/**
+ * Goes to a different collector, but remembers the previous collector.
+ */
+void PStatFlameGraph::
+push_collector_index(int collector_index) {
+  if (_collector_index != collector_index) {
+    _history.push_back(_collector_index);
+    set_collector_index(collector_index);
+  }
+}
+
+/**
+ * Goes to the previous visited collector.  Returns true if the history stack
+ * was non-empty.
+ */
+bool PStatFlameGraph::
+pop_collector_index() {
+  if (!_history.empty()) {
+    int collector_index = _history.back();
+    _history.pop_back();
+    set_collector_index(collector_index);
+    return true;
+  }
+  return false;
+}
+
 /**
  * Changes the frame number shown by this flame graph.  This may force a redraw.
  */

pandatool/src/pstatserver/pStatFlameGraph.h

@@ -45,6 +45,10 @@ public:
   INLINE int get_thread_index() const;
   INLINE int get_collector_index() const;
   void set_collector_index(int collector_index);
+  void push_collector_index(int collector_index);
+  bool pop_collector_index();
+  INLINE void clear_history();
+  INLINE size_t get_history_depth() const;
 
   INLINE int get_frame_number() const;
   void set_frame_number(int collector_index);
@@ -137,6 +141,8 @@ private:
   double _time_width;
   int _current_frame;
   bool _title_unknown;
+
+  std::vector<int> _history;
 };
 
 #include "pStatFlameGraph.I"