fix theme change handling - close buggins/dlangide#132

src/dlangui/widgets/controls.d

@@ -213,6 +213,7 @@ class ImageWidget : Widget {
 
     /// handle theme change: e.g. reload some themed resources
     override void onThemeChanged() {
+        super.onThemeChanged();
         if (_drawableId !is null)
             _drawable.clear(); // remove cached drawable
     }

src/dlangui/widgets/lists.d

@@ -886,6 +886,16 @@ class ListWidget : WidgetGroup, OnScrollHandler, OnAdapterChangeHandler {
         return true;
     }
 
+    /// handle theme change: e.g. reload some themed resources
+    override void onThemeChanged() {
+        super.onThemeChanged();
+        _scrollbar.onThemeChanged();
+        for (int i = 0; i < itemCount; i++) {
+            Widget w = itemWidget(i);
+            w.onThemeChanged();
+        }
+    }
+
     /// Measure widget according to desired width and height constraints. (Step 1 of two phase layout).
     override void measure(int parentWidth, int parentHeight) {
         if (visibility == Visibility.Gone) {

src/dlangui/widgets/widget.d

@@ -255,13 +255,15 @@ public:
 
     /// handle theme change: e.g. reload some themed resources
     void onThemeChanged() {
-        _cachedStyle = currentTheme.get(_styleId);
         // default implementation: call recursive for children
         for (int i = 0; i < childCount; i++)
             child(i).onThemeChanged();
         if (_ownStyle) {
             _ownStyle.onThemeChanged();
         }
+        if (_cachedStyle) {
+            _cachedStyle = currentTheme.get(_styleId);
+        }
     }
 
     /// returns widget id, null if not set