double click to instant creation

diylc/diylc-swing/src/main/java/org/diylc/swing/plugins/statusbar/StatusBar.java

@@ -82,7 +82,8 @@ public class StatusBar extends JPanel implements IPlugIn {
   private static final String HOLD_TO_UNSTUCK = LangUtil.translate("hold %s and drag to unstick from");
   private static final String SELECTION = LangUtil.translate("Selection");
   private static final String DRAG_POINTS_OF = LangUtil.translate("Drag control point(s) of");
-  private static final String DRAG_TO_PLACE_A_NEW = LangUtil.translate("Drag the mouse over the canvas to place a new");
+  private static final String DRAG_TO_PLACE_A_NEW =
+      LangUtil.translate("Click or drag over the canvas to place a new");
   private static final String ZOOM = LangUtil.translate("Zoom");
   private static final String SELECTION_SIZE = LangUtil.translate("Selection Size");
   private static final String SELECTION_IS_EMPTY = LangUtil.translate("Selection is empty.");

diylc/diylc-swing/src/main/java/org/diylc/swing/plugins/toolbox/ComponentButtonFactory.java

@@ -94,6 +94,19 @@ public class ComponentButtonFactory {
 
     button.addMouseListener(new MouseAdapter() {
 
+      /**
+       * Runs after the button has already fired its action for this click, so re-arming the slot
+       * here is what decides the mode: a double click instantiates the component up front so that
+       * it follows the cursor and drops in a single gesture, the way dragging it onto the canvas
+       * does, instead of asking for a point at a time.
+       */
+      @Override
+      public void mouseClicked(MouseEvent e) {
+        if (SwingUtilities.isLeftMouseButton(e) && e.getClickCount() > 1) {
+          plugInPort.setNewComponentTypeSlot(componentType, null, null, true);
+        }
+      }
+
       @Override
       public void mousePressed(MouseEvent e) {
         if (e.getButton() == MouseEvent.BUTTON3) {

diylc/diylc-swing/src/main/java/org/diylc/swing/plugins/tree/CustomTreeModel.java

@@ -123,13 +123,7 @@ public class CustomTreeModel implements TreeModel {
         if (fav.getType() == FavoriteType.Component) {
           ComponentType type = this.typesByClass.get(fav.getName());
           if (this.searchText == null || type.getName().toLowerCase().contains(this.searchText)) {
-            visibleTypes.add(new TreeNode(type, new MouseAdapter() {
-
-              @Override
-              public void mouseClicked(MouseEvent e) {
-                plugInPort.setNewComponentTypeSlot(type, null, null, false);
-              }
-            }));
+            visibleTypes.add(new TreeNode(type, createComponentClickListener(type)));
           }
         } else {
           // block
@@ -189,13 +183,7 @@ public class CustomTreeModel implements TreeModel {
         if (type == null)
           continue;
         if (this.searchText == null || type.getName().toLowerCase().contains(this.searchText)) {
-          visibleTypes.add(new TreeNode(type, new MouseAdapter() {
-
-            @Override
-            public void mouseClicked(MouseEvent e) {
-              plugInPort.setNewComponentTypeSlot(type, null, null, false);
-            }
-          }));
+          visibleTypes.add(new TreeNode(type, createComponentClickListener(type)));
         }
       }
     }
@@ -230,17 +218,29 @@ public class CustomTreeModel implements TreeModel {
             || category.toLowerCase().contains(this.searchText.toLowerCase()) ||
 
             typeMatches(this.searchText, type))
-          visibleTypes.add(new TreeNode(type, new MouseAdapter() {
-
-            @Override
-            public void mouseClicked(MouseEvent e) {
-              plugInPort.setNewComponentTypeSlot(type, null, null, false);
-            }
-          }));
+          visibleTypes.add(new TreeNode(type, createComponentClickListener(type)));
     this.visibleLeaves.put(category, visibleTypes);
     return visibleTypes;
   }
 
+  /**
+   * Arms the slot for the specified type. A double click instantiates the component up front so
+   * that it follows the cursor and drops in a single gesture, the way dragging it onto the canvas
+   * does, instead of asking for a point at a time.
+   *
+   * @param type
+   * @return listener to attach to the tree node.
+   */
+  private MouseAdapter createComponentClickListener(ComponentType type) {
+    return new MouseAdapter() {
+
+      @Override
+      public void mouseClicked(MouseEvent e) {
+        plugInPort.setNewComponentTypeSlot(type, null, null, e != null && e.getClickCount() > 1);
+      }
+    };
+  }
+
   private boolean typeMatches(String searchText, ComponentType type) {
     if (searchText == null || searchText.isEmpty())
       return true;

diylc/diylc-swing/src/main/java/org/diylc/swing/plugins/tree/TreePanel.java

@@ -258,17 +258,15 @@ public class TreePanel extends JPanel {
         /**
          * Prefer release over click: {@code mouseClicked} is not posted if the cursor moves
          * between press and release (common with DnD or hand jitter), while selection may still
-         * change — then re-clicks on the same row fire no selection event.
+         * change - then re-clicks on the same row fire no selection event. Every release is
+         * forwarded rather than only the first, so that the listener can tell a double click from
+         * a single one; re-arming the slot on the second release is harmless.
          */
         @Override
         public void mouseReleased(MouseEvent e) {
           if (SwingUtilities.isRightMouseButton(e) || e.isPopupTrigger()) {
             return;
           }
-          if (e.getClickCount() != 1) {
-            return;
-          }
-
           TreePath path = tree.getPathForLocation(e.getX(), e.getY());
           if (path == null) {
             path = tree.getClosestPathForLocation(e.getX(), e.getY());