rearrange example widgets using tabs

examples/example1/main.d

@@ -2,6 +2,7 @@ module winmain;
 
 import dlangui.all;
 import std.stdio;
+import std.conv;
 
 version (linux) {
 	pragma(lib, "png");
@@ -97,22 +98,19 @@ extern (C) int UIAppMain(string[] args) {
 		layout.childById("BTN2").onClickListener(delegate (Widget w) { Log.d("onClick ", w.id); return true; });
 		layout.childById("BTN3").onClickListener(delegate (Widget w) { Log.d("onClick ", w.id); return true; });
 
-        ListWidget list = new ListWidget("mylist", Orientation.Horizontal);
-        WidgetListAdapter listAdapter = new WidgetListAdapter();
-        listAdapter.widgets.add((new TextWidget()).text("List item 1"));
-        listAdapter.widgets.add((new TextWidget()).text("List item 2"));
-        listAdapter.widgets.add((new TextWidget()).text("List item 3"));
-        listAdapter.widgets.add((new TextWidget()).text("List item 4"));
-        listAdapter.widgets.add((new TextWidget()).text("List item 5"));
-        listAdapter.widgets.add((new TextWidget()).text("List item 6"));
-        list.ownAdapter = listAdapter;
-        list.layoutWidth(FILL_PARENT);
-        layout.addChild(list);
 
 		layout.layoutHeight(FILL_PARENT).layoutWidth(FILL_PARENT);
 
         tabs.addTab(layout, "Tab 1"d);
-        tabs.addTab((new TextWidget()).id("tab2").textColor(0x00802000).text("Tab 2 contents bla bla bla"), "Tab 2"d);
+
+        ListWidget list = new ListWidget("tab2", Orientation.Vertical);
+        WidgetListAdapter listAdapter = new WidgetListAdapter();
+        for (int i = 0; i < 1000; i++)
+            listAdapter.widgets.add((new TextWidget()).text("List item "d ~ to!dstring(i)));
+        list.ownAdapter = listAdapter;
+        list.layoutWidth(FILL_PARENT).layoutHeight(FILL_PARENT);
+        tabs.addTab(list, "Lists"d);
+
         tabs.addTab((new TextWidget()).id("tab3").textColor(0x00802000).text("Tab 3 contents"), "Tab 3"d);
         tabs.addTab((new TextWidget()).id("tab4").textColor(0x00802000).text("Tab 4 contents some long string"), "Tab 4"d);
         tabs.addTab((new TextWidget()).id("tab5").textColor(0x00802000).text("Tab 5 contents"), "Tab 5"d);

src/dlangui/core/logger.d

@@ -19,6 +19,10 @@ void setLogLevel(LogLevel level) {
 	logLevel = level;
 }
 
+long currentTimeMillis() {
+    return std.datetime.Clock.currStdTime / 10000;
+}
+
 void setStdoutLogger() {
 	logFile = stdout;
 }

src/dlangui/platforms/common/platform.d

@@ -73,10 +73,18 @@ class Window {
                 checkUpdateNeeded(needDraw, needLayout, animationActive);
             }
             if (needLayout) {
+                long measureStart = currentTimeMillis;
                 _mainWidget.measure(_dx, _dy);
+                long measureEnd = currentTimeMillis;
+                Log.d("measure took ", measureEnd - measureStart, " ms");
                 _mainWidget.layout(Rect(0, 0, _dx, _dy));
+                long layoutEnd = currentTimeMillis;
+                Log.d("layout took ", layoutEnd - measureEnd, " ms");
             }
+            long drawStart = currentTimeMillis;
             _mainWidget.onDraw(buf);
+            long drawEnd = currentTimeMillis;
+            Log.d("draw took ", drawEnd - drawStart, " ms");
             lastDrawTs = ts;
             if (animationActive)
                 scheduleAnimation();

src/dlangui/platforms/windows/winapp.d

@@ -306,6 +306,7 @@ class Win32Window : Window {
 
     void onPaint() {
         Log.d("onPaint()");
+        long paintStart = currentTimeMillis;
         version (USE_OPENGL) {
             if (useOpengl && _hGLRC) {
                 paintUsingOpenGL();
@@ -315,6 +316,8 @@ class Win32Window : Window {
         } else {
             paintUsingGDI();
         }
+        long paintEnd = currentTimeMillis;
+        Log.d("WM_PAINT handling took ", paintEnd - paintStart, " ms");
     }
 
 	protected ButtonDetails _lbutton;

src/dlangui/widgets/lists.d

@@ -383,17 +383,19 @@ class ListWidget : WidgetGroup, OnScrollHandler {
         // todo: scrollOffset
         // draw items
         for (int i = 0; i < itemCount; i++) {
-            Widget w = itemWidget(i);
-            if (w is null || w.visibility != Visibility.Visible)
-                continue;
             Rect itemrc = _itemRects[i];
             itemrc.left += rc.left - scrollOffset.x;
             itemrc.right += rc.left - scrollOffset.x;
             itemrc.top += rc.top - scrollOffset.y;
             itemrc.bottom += rc.top - scrollOffset.y;
-            w.measure(itemrc.width, itemrc.height);
+            if (itemrc.intersects(rc)) {
-            w.layout(itemrc);
+                Widget w = itemWidget(i);
-			w.onDraw(buf);
+                if (w is null || w.visibility != Visibility.Visible)
+                    continue;
+                w.measure(itemrc.width, itemrc.height);
+                w.layout(itemrc);
+			    w.onDraw(buf);
+            }
 		}
     }