Canvas widgets: Difference between revisions

Canvas widgets (view source)

1,026 bytes added , 29 June 2014

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20,741

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 * Checkbox
 * ScrollArea
+New widgets are implemented by adding a corresponding Nasal file to $FG_ROOT/Nasal/canvas/gui/widgets - e.g. myWidget.nas
+Each widget should then implement a minimal interface, for example:
+<syntaxhighlight lang="nasal">
+gui.widgets.myWidget = {
+  new: func(parent, style, cfg)
+  {
+    var m = gui.Widget.new(gui.widgets.myWidget);
+    m._cfg = Config.new(cfg);
+    m._focus_policy = m.NoFocus;
+    m._setView( style.createWidget(parent, "mywidget", m._cfg) );
+    return m;
+  },
+  setImage: func(img)
+  {
+    me._view.setImage(me, img);
+    return me;
+  },
+  setBackground: func(bg)
+  {
+    me._view.setBackground(me, bg);
+    return me;
+  }
+};
+</syntaxhighlight>
+For this to work, the next thing that needs to be done is opening $FG_ROOT/Nasal/canvas/gui/styles/DefaultStyle.nas in order to add a default style for your new widget to the end of the file, the hash entry's name must match the key used in the _setView() method call above (e.g. mywidget in this case):
+<syntaxhighlight lang="nasal">
+</syntaxhighlight>
 == Widget Candidates ==