feat: Add alignment of a selection of items. For feature #328.

gui-js/apps/minsky-electron/src/app/managers/ContextMenuManager.ts

@@ -528,6 +528,10 @@ export class ContextMenuManager {
         label: 'Add item to a publication tab',
         submenu: await ContextMenuManager.pubTabMenu(),
       }),
+      new MenuItem({
+        label: 'Align',
+        submenu: Menu.buildFromTemplate(this.alignmentMenu()),
+      }),
       new MenuItem({
         label: `Delete ${itemInfo.classType}`,
         click: () => CommandsManager.deleteCurrentItemHavingId(itemInfo.id)
@@ -1403,5 +1407,24 @@ export class ContextMenuManager {
       ]);
     menu.popup();
   }
+
+  static alignmentMenu() {
+     const labels: [string, string][] = [
+       ['left', 'Left'],
+       ['centre', 'Centre'],
+       ['right', 'Right'],
+       ['left_right', 'Left & Right'],
+       ['top', 'Top'],
+       ['middle', 'Middle'],
+       ['bottom', 'Bottom'],
+       ['top_bottom', 'Top & Bottom'],
+     ];
+    return labels.map(([alignment, label]) =>
+       new MenuItem({
+         label,
+         click: async ()=>{await minsky.canvas.alignSelection(alignment);},
+       })
+     );
+  }
 }
 

gui-js/libs/shared/src/lib/backend/minsky.ts

@@ -432,6 +432,7 @@ export class Canvas extends RenderNativeWindow {
   async addSheet(): Promise<void> {return this.$callMethod('addSheet');}
   async addSwitch(): Promise<void> {return this.$callMethod('addSwitch');}
   async addVariable(a1: string,a2: string): Promise<void> {return this.$callMethod('addVariable',a1,a2);}
+  async alignSelection(a1: string): Promise<void> {return this.$callMethod('alignSelection',a1);}
   async applyDefaultPlotOptions(): Promise<void> {return this.$callMethod('applyDefaultPlotOptions');}
   async clickType(...args: string[]): Promise<string> {return this.$callMethod('clickType',...args);}
   async closestInPort(a1: number,a2: number): Promise<object> {return this.$callMethod('closestInPort',a1,a2);}
@@ -1941,6 +1942,7 @@ export class Selection extends CppClass {
   async addWire(...args: any[]): Promise<object> {return this.$callMethod('addWire',...args);}
   async adjustBookmark(): Promise<void> {return this.$callMethod('adjustBookmark');}
   async adjustWiresGroup(a1: Wire): Promise<void> {return this.$callMethod('adjustWiresGroup',a1);}
+  async align(a1: Item,a2: string): Promise<void> {return this.$callMethod('align',a1,a2);}
   async arguments(): Promise<string> {return this.$callMethod('arguments');}
   async autoLayout(): Promise<void> {return this.$callMethod('autoLayout');}
   async bookmark(...args: boolean[]): Promise<boolean> {return this.$callMethod('bookmark',...args);}

model/canvas.h

@@ -161,6 +161,15 @@ namespace minsky
     /// select all items in a given region
     void select(const LassoBox&);
 
+    /// align items in selection using the current context item as the anchor.
+    /// No-op when there is no current item (for example, no right-clicked item);
+    /// callers should only expose/enable this action when an anchor item exists.
+    void alignSelection(Selection::Align align)
+    {
+      if (item)
+        selection.align(*item,align);
+    }
+
     int ravelsSelected() const; ///< number of ravels in selection
 
     /// sets itemFocus, and resets mouse offset for placement

model/selection.cc

@@ -117,7 +117,45 @@ namespace minsky
           return true;
     return false;
   }
-
+
+  void Selection::align(const Item& ref, Align align)
+  {
+    auto apply=[&](const auto& i)
+    {
+      switch (align)
+        {
+        case left:
+          i->moveTo(i->x()+ref.left()-i->left(), i->y());
+          break;
+        case centre:
+          i->moveTo(ref.x(), i->y());
+          break;
+        case right:
+          i->moveTo(i->x()+ref.right()-i->right(), i->y());
+          break;
+        case left_right:
+          i->iWidth(ref.iWidth());
+          i->moveTo(ref.x(), i->y());
+          break;
+        case top:
+          i->moveTo(i->x(), i->y()+ref.top()-i->top());
+          break;
+        case middle:
+          i->moveTo(i->x(), ref.y());
+          break;
+        case bottom:
+          i->moveTo(i->x(), i->y()+ref.bottom()-i->bottom());
+          break;
+        case top_bottom:
+          i->iHeight(ref.iHeight());
+          i->moveTo(i->x(), ref.y());
+          break;
+        }
+    };
+
+    for (auto& i: items) apply(i);
+    for (auto& g: groups) apply(g);
+  }
 }
 
 CLASSDESC_ACCESS_EXPLICIT_INSTANTIATION(minsky::Selection);

model/selection.h

@@ -53,6 +53,10 @@ namespace minsky
     /// return if item is contained in selection
     bool contains(const ItemPtr& item) const;
     using Item::contains;
+
+    enum Align {left, centre, right, left_right, top, middle, bottom, top_bottom};
+    /// Align items in this selection with the reference item 
+    void align(const Item&, Align);
   };
 
 }