list and focus handling fixes

examples/example1/main.d

@@ -139,12 +139,14 @@ extern (C) int UIAppMain(string[] args) {
             for (int i = 0; i < 1000; i++)
                 listAdapter.widgets.add((new TextWidget()).text("List item "d ~ to!dstring(i)).styleId("LIST_ITEM"));
             list.ownAdapter = listAdapter;
+            listAdapter.resetItemState(0, State.Enabled);
             listAdapter.resetItemState(5, State.Enabled);
             listAdapter.resetItemState(7, State.Enabled);
             listAdapter.resetItemState(12, State.Enabled);
             assert(list.itemEnabled(5) == false);
             assert(list.itemEnabled(6) == true);
             list.layoutWidth(FILL_PARENT).layoutHeight(FILL_PARENT);
+            list.selectItem(0);
             tabs.addTab(list, "Long List"d);
         }
 

src/dlangui/core/types.d

@@ -240,6 +240,7 @@ enum State : uint {
     Checked = 64,
     Activated = 128,
     WindowFocused = 256,
+    Default = 512, // widget is default for form (e.g. default button will be focused on show)
     Parent = 0x10000, // use parent's state
 }
 

src/dlangui/widgets/layouts.d

@@ -363,17 +363,21 @@ class FrameLayout : WidgetGroup {
     }
 
     /// make one of children (with specified ID) visible, for the rest, set visibility to otherChildrenVisibility
-    bool showChild(string ID, Visibility otherChildrenVisibility = Visibility.Invisible) {
+    bool showChild(string ID, Visibility otherChildrenVisibility = Visibility.Invisible, bool updateFocus = false) {
         bool found = false;
+        Widget foundWidget = null;
 		for (int i = 0; i < _children.count; i++) {
 			Widget item = _children.get(i);
             if (item.compareId(ID)) {
                 item.visibility = Visibility.Visible;
+                foundWidget = item;
                 found = true;
             } else {
                 item.visibility = otherChildrenVisibility;
             }
 		}
+        if (foundWidget !is null && updateFocus)
+            foundWidget.setFocus();
         return found;
     }
 }

src/dlangui/widgets/lists.d

@@ -224,13 +224,19 @@ class ListWidget : WidgetGroup, OnScrollHandler {
     void makeSelectionVisible() {
         if (_selectedItemIndex < 0)
             return; // no selection
+        if (needLayout) {
+            _makeSelectionVisibleOnNextLayout = true;
+            return;
+        }
         makeItemVisible(_selectedItemIndex);
     }
 
+    protected bool _makeSelectionVisibleOnNextLayout;
     /// ensure item is visible
     void makeItemVisible(int itemIndex) {
         if (itemIndex < 0 || itemIndex >= itemCount)
             return; // no selection
+
         Rect viewrc = Rect(0, 0, _clientRc.width, _clientRc.height);
         Rect scrolledrc = itemRect(itemIndex);
         if (scrolledrc.isInsideOf(viewrc)) // completely visible
@@ -284,7 +290,23 @@ class ListWidget : WidgetGroup, OnScrollHandler {
         return true;
     }
 
-	protected bool selectItem(int index) {
+	bool selectItem(int index, int disabledItemsSkipDirection) {
+        if (index == -1 || disabledItemsSkipDirection == 0)
+            return selectItem(index);
+        int maxAttempts = itemCount;
+        for (int i = 0; i < maxAttempts; i++) {
+            if (selectItem(index))
+                return true;
+            index += disabledItemsSkipDirection > 0 ? 1 : -1;
+            if (index < 0)
+                index = itemCount - 1;
+            if (index >= itemCount)
+                index = 0;
+        }
+        return false;
+    }
+
+	bool selectItem(int index) {
 		if (_selectedItemIndex == index) {
             updateSelectedItemFocus();
             makeSelectionVisible();
@@ -530,6 +552,11 @@ class ListWidget : WidgetGroup, OnScrollHandler {
 
         // calc item rectangles
         updateItemPositions();
+
+        if (_makeSelectionVisibleOnNextLayout) {
+            makeSelectionVisible();
+            _makeSelectionVisibleOnNextLayout = false;
+        }
     }
 
     /// Draw widget at its position to buffer
@@ -593,13 +620,17 @@ class ListWidget : WidgetGroup, OnScrollHandler {
         }
         if (event.action == KeyAction.KeyDown) {
             if (event.keyCode == KeyCode.HOME) {
-                // select first item on HOME key
+                // select first enabled item on HOME key
-                selectItem(0);
+                selectItem(0, 1);
                 return true;
             } else if (event.keyCode == KeyCode.END) {
-                // select last item on END key
+                // select last enabled item on END key
-                selectItem(itemCount - 1);
+                selectItem(itemCount - 1, -1);
                 return true;
+            } else if (event.keyCode == KeyCode.PAGEDOWN) {
+                // TODO
+            } else if (event.keyCode == KeyCode.PAGEUP) {
+                // TODO
             }
         }
         return false;

src/dlangui/widgets/tabs.d

@@ -370,7 +370,7 @@ class TabHost : FrameLayout, TabHandler {
 
     protected override void onTabChanged(string newActiveTabId, string previousTabId) {
         if (newActiveTabId !is null) {
-            showChild(newActiveTabId);
+            showChild(newActiveTabId, Visibility.Invisible, true);
         }
         if (_onTabChanged !is null)
             _onTabChanged(newActiveTabId, previousTabId);

src/dlangui/widgets/widget.d

@@ -323,14 +323,49 @@ class Widget {
     @property bool focused() {
         return (window !is null && window.focusedWidget is this && (state & State.Focused));
     }
-    /// sets focus to this widget, returns previously focused widget
+    /// returns true if this widget and all its parents are visible
+    @property bool visible() {
+        if (visibility != Visibility.Visible)
+            return false;
+        if (parent is null)
+            return true;
+        return parent.visible;
+    }
+    /// returns true if widget is focusable and visible
+    @property bool canFocus() {
+        return focusable && visible;
+    }
+    /// sets focus to this widget or suitable focusable child, returns previously focused widget
     Widget setFocus() {
         if (window is null)
             return null;
-        if (!_focusable)
+        if (!visible)
             return window.focusedWidget;
+        if (!canFocus) {
+            Widget w = findFocusableChild(true);
+            if (!w)
+                w = findFocusableChild(false);
+            if (w)
+                return window.setFocus(w);
+            // try to find focusable child
+            return window.focusedWidget;
+        }
         return window.setFocus(this);
     }
+    /// searches children for first focusable item, returns null if not found
+    Widget findFocusableChild(bool defaultOnly) {
+        for(int i = 0; i < childCount; i++) {
+            Widget w = child(i);
+            if (w.canFocus && (!defaultOnly || (w.state & State.Default) != 0))
+                return w;
+            w = w.findFocusableChild(defaultOnly);
+            if (w !is null)
+                return w;
+        }
+        if (canFocus)
+            return this;
+        return null;
+    }
 
     // =======================================================
     // Events