tree widget, continue development

src/dlangui/widgets/tree.d

@@ -4,6 +4,113 @@ import dlangui.widgets.widget;
 import dlangui.widgets.controls;
 import dlangui.widgets.scroll;
 import std.conv;
+import std.algorithm;
+
+// tree widget item data container
+class TreeItem {
+    protected TreeItem _parent;
+    protected string _id;
+    protected string _iconRes;
+    protected int _level;
+    protected UIString _text;
+    protected ObjectList!TreeItem _children;
+    protected bool _expanded;
+
+    @property TreeItem parent() { return _parent; }
+    @property protected TreeItem parent(TreeItem p) { _parent = p; return this; }
+    @property string id() { return _id; }
+    @property TreeItem id(string id) { _id = id; return this; }
+    @property string iconRes() { return _iconRes; }
+    @property TreeItem iconRes(string res) { _iconRes = res; return this; }
+    @property int level() { return _level; }
+    @property protected TreeItem level(int level) { 
+        _level = level;
+        for (int i = 0; i < childCount; i++)
+            child(i).level = _level + 1;
+        return this; 
+    }
+    @property bool expanded() { return _expanded; }
+    @property protected TreeItem expanded(bool expanded) { _expanded = expanded; return this; }
+    bool isFullyExpanded() {
+        if (!_expanded)
+            return false;
+        if (_parent)
+            return _parent.isFullyExpanded();
+        return false;
+    }
+    void expand() {
+        _expanded = true;
+        if (_parent)
+            _parent.expand();
+    }
+
+    /// get widget text
+    @property dstring text() { return _text; }
+    /// set text to show
+    @property TreeItem text(dstring s) {
+        _text = s; 
+		return this;
+    }
+    /// set text to show
+    @property TreeItem text(UIString s) { 
+        _text = s;
+		return this;
+    }
+    /// set text resource ID to show
+    @property TreeItem textResource(string s) {
+        _text = s; 
+		return this;
+    }
+
+    bool compareId(string id) {
+        return _id !is null && _id.equal(id);
+    }
+
+    @property TreeItem topParent() {
+        if (!_parent)
+            return this;
+        return _parent.topParent;
+    }
+
+    /// returns number of children of this widget
+    @property int childCount() { return _children.count; }
+    /// returns child by index
+    TreeItem child(int index) { return _children.get(index); }
+    /// adds child, returns added item
+    TreeItem addChild(TreeItem item) { 
+        return _children.add(item).parent(this).level(_level + 1);
+    }
+    /// removes child, returns removed item
+    TreeItem removeChild(int index) { 
+        TreeItem res = _children.remove(index);
+        if (res !is null)
+            res.parent = null;
+        return res;
+    }
+    /// removes child by ID, returns removed item
+    TreeItem removeChild(string ID) {
+        TreeItem res = null;
+        int index = _children.indexOf(ID);
+        if (index < 0)
+            return null;
+        res = _children.remove(index); 
+        if (res !is null)
+            res.parent = null;
+        return res;
+    }
+    /// returns index of widget in child list, -1 if passed widget is not a child of this widget
+    int childIndex(TreeItem item) { return _children.indexOf(item); }
+
+}
+
+interface OnTreeContentChangeListener {
+    void onTreeContentChange(TreeItems source);
+}
+
+class TreeItems : TreeItem {
+    // signal handler OnTreeContentChangeListener
+    Listener!OnTreeContentChangeListener listener;
+}
 
 class TreeWidgetBase :  ScrollWidgetBase {
 

src/dlangui/widgets/widget.d

@@ -1210,26 +1210,26 @@ class Widget {
 	
 }
 
-/// widget list holder
-struct WidgetList {
-    protected Widget[] _list;
+/// object list holder, owning its objects - on destroy of holder, all own objects will be destroyed
+struct ObjectList(T) {
+    protected T[] _list;
     protected int _count;
     /// returns count of items
     @property int count() const { return _count; }
     /// get item by index
-    Widget get(int index) {
+    T get(int index) {
         assert(index >= 0 && index < _count, "child index out of range");
         return _list[index];
     }
     /// add item to list
-    Widget add(Widget item) {
+    T add(T item) {
         if (_list.length <= _count) // resize
             _list.length = _list.length < 4 ? 4 : _list.length * 2;
         _list[_count++] = item;
         return item;
     }
     /// add item to list
-    Widget insert(Widget item, int index = -1) {
+    T insert(T item, int index = -1) {
         if (index > _count || index < 0)
             index = _count;
         if (_list.length <= _count) // resize
@@ -1241,23 +1241,25 @@ struct WidgetList {
         return item;
     }
     /// find child index for item, return -1 if not found
-    int indexOf(Widget item) {
+    int indexOf(T item) {
         for (int i = 0; i < _count; i++)
             if (_list[i] == item)
                 return i;
         return -1;
     }
     /// find child index for item by id, return -1 if not found
-    int indexOf(string id) {
-        for (int i = 0; i < _count; i++)
-            if (_list[i].compareId(id))
-                return i;
-        return -1;
+    static if (__traits(hasMember, T, "compareId")) {
+        int indexOf(string id) {
+            for (int i = 0; i < _count; i++)
+                if (_list[i].compareId(id))
+                    return i;
+            return -1;
+        }
     }
     /// remove item from list, return removed item
-    Widget remove(int index) {
+    T remove(int index) {
         assert(index >= 0 && index < _count, "child index out of range");
-        Widget item = _list[index];
+        T item = _list[index];
         for (int i = index; i < _count - 1; i++)
             _list[i] = _list[i + 1];
         _count--;
@@ -1276,6 +1278,9 @@ struct WidgetList {
     }
 }
 
+/// widget list holder
+alias WidgetList = ObjectList!Widget;
+
 /// base class for widgets which have children
 class WidgetGroup : Widget {