Now you can press a mouse button in a ComboBoxEntry and drag the mouse to the ComboBoxListBox (issue 339)

src/ui/combobox.cpp

@@ -411,8 +411,33 @@ bool ComboBoxEntry::onProcessMessage(Message* msg)
       if (m_comboBox->isEditable()) {
         getManager()->setFocus(this);
       }
-      else
+      else {
+        captureMouse();
         return true;
+      }
+      break;
+
+    case kMouseUpMessage:
+      if (hasCapture())
+        releaseMouse();
+      break;
+
+    case kMouseMoveMessage:
+      if (hasCapture()) {
+        MouseMessage* mouseMsg = static_cast<MouseMessage*>(msg);
+        Widget* pick = getManager()->pick(mouseMsg->position());
+        Widget* listbox = m_comboBox->m_listbox;
+
+        if (pick != NULL && (pick == listbox || pick->hasAncestor(listbox))) {
+          releaseMouse();
+
+          MouseMessage mouseMsg(kMouseDownMessage,
+            mouseMsg->buttons(),
+            mouseMsg->position());
+          pick->sendMessage(&mouseMsg);
+          return true;
+        }
+      }
       break;
 
   }

src/ui/combobox.h

@@ -22,10 +22,12 @@ namespace ui {
   class ListItem;
   class Window;
 
+  class ComboBoxEntry;
   class ComboBoxListBox;
 
   class ComboBox : public Widget
   {
+    friend class ComboBoxEntry;
     friend class ComboBoxListBox;
 
   public:
@@ -91,7 +93,7 @@ namespace ui {
   private:
     void onButtonClick(Event& ev);
 
-    Entry* m_entry;
+    ComboBoxEntry* m_entry;
     Button* m_button;
     Window* m_window;
     ComboBoxListBox* m_listbox;

src/ui/widget.cpp

@@ -427,6 +427,15 @@ bool Widget::hasChild(Widget* child)
   return std::find(m_children.begin(), m_children.end(), child) != m_children.end();
 }
 
+bool Widget::hasAncestor(Widget* ancestor)
+{
+  for (Widget* widget=m_parent; widget; widget=widget->m_parent) {
+    if (widget == ancestor)
+      return true;
+  }
+  return false;
+}
+
 Widget* Widget::findChild(const char* id)
 {
   Widget* child;

src/ui/widget.h

@@ -208,6 +208,7 @@ namespace ui {
 
     Widget* pick(const gfx::Point& pt);
     bool hasChild(Widget* child);
+    bool hasAncestor(Widget* ancestor);
     Widget* findChild(const char* id);
 
     // Returns a widget in the same window that is located "sibling".