Enables selection of bubbles using an invisible text view

src/transcript/transcript-drawing-area.vala

@@ -16,6 +16,9 @@ private class TranscriptDrawingArea : Widget
         }
     }
 
+    public signal void on_text_bubble_hover(VisibleTextLayout? text_bubble);
+    public signal void on_text_bubble_click(VisibleTextLayout? text_bubble);
+
     private ArrayList<Message> _messages = new ArrayList<Message>();
     private ArrayList<ChatItemLayout> _chat_items = new ArrayList<ChatItemLayout>();
 
@@ -26,6 +29,7 @@ private class TranscriptDrawingArea : Widget
     private Gdk.Rectangle? _click_bounding_box = null;
 
     private EventControllerMotion _motion_controller = new EventControllerMotion();
+    private ArrayList<VisibleTextLayout?> _visible_text_layouts = new ArrayList<VisibleTextLayout?>();
 
     private const bool debug_viewport = false;
     private uint? _tick_callback_id = null;
@@ -36,9 +40,9 @@ private class TranscriptDrawingArea : Widget
         
         weak TranscriptDrawingArea self = this;
 
-        _click_gesture.button = Gdk.BUTTON_SECONDARY;
+        _click_gesture.button = Gdk.BUTTON_SECONDARY | Gdk.BUTTON_PRIMARY;
         _click_gesture.begin.connect(() => {
-            self.on_right_click();
+            self.on_click(self._click_gesture.get_button());
         });
         add_controller(_click_gesture);
 
@@ -129,6 +133,7 @@ private class TranscriptDrawingArea : Widget
         // Draw each item in reverse order, since the messages are in reverse order
         float y_offset = 0;
         int container_width = get_width();
+        _visible_text_layouts.clear();
         for (int i = _chat_items.size - 1; i >= 0; i--) {
             var chat_item = _chat_items[i];
             var item_width = chat_item.get_width();
@@ -152,6 +157,10 @@ private class TranscriptDrawingArea : Widget
             // Skip drawing if this item is not in the viewport
             float height_offset = 0.0f;
             if (viewport_rect.intersection(rect, null)) {
+                if (chat_item is TextBubbleLayout) {
+                    _visible_text_layouts.add(VisibleTextLayout(chat_item as TextBubbleLayout, rect));
+                }
+
                 snapshot.save();
 
                 var pushed_opacity = false;
@@ -190,8 +199,35 @@ private class TranscriptDrawingArea : Widget
         animation_tick();
     }
 
+    private VisibleTextLayout? get_text_bubble_at(double x, double y) {
+        foreach (var layout in _visible_text_layouts) {
+            if (layout.rect.contains_point(Graphene.Point() { x = (float)x, y = (float)y })) {
+                return layout;
+            }
+        }
+
+        return null;
+    }
+
     private void on_mouse_motion(double x, double y) {
-        // TODO: Will be making temporary text views here. 
+        VisibleTextLayout? hovered_text_bubble = get_text_bubble_at(x, y);
+        on_text_bubble_hover(hovered_text_bubble);
+    }
+
+    private void on_click(uint button) {
+        if (button == Gdk.BUTTON_SECONDARY) {
+            on_right_click();
+        } else if (button == Gdk.BUTTON_PRIMARY) {
+            on_left_click();
+        }
+    }
+
+    private void on_left_click() {
+        Gdk.Rectangle? bounding_box = null;
+        if (_click_gesture.get_bounding_box(out bounding_box)) {
+            var text_bubble = get_text_bubble_at(bounding_box.x, bounding_box.y);
+            on_text_bubble_click(text_bubble);
+        }
     }
 
     private void on_right_click() {
@@ -372,4 +408,14 @@ private class ChatItemAnimation
     private static double ease_out_quart(double t) {
         return 1.0 - Math.pow(1.0 - t, 4);
     }
+}
+
+public struct VisibleTextLayout {
+    public weak TextBubbleLayout text_bubble;
+    public Graphene.Rect rect;
+
+    public VisibleTextLayout(TextBubbleLayout text_bubble, Graphene.Rect rect) {
+        this.text_bubble = text_bubble;
+        this.rect = rect;
+    }
 }