[Mac] Enables drag N' drop for the buttons within the Browser Actions contain...

chrome/browser/cocoa/extensions/browser_actions_controller.mm

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "browser_actions_controller.h"
 
+#include <cmath>
 #include <string>
 
 #include "app/resource_bundle.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/pref_service.h"
 #import "chrome/browser/cocoa/extensions/browser_action_button.h"
 #import "chrome/browser/cocoa/extensions/browser_actions_container_view.h"
 #import "chrome/browser/cocoa/extensions/extension_popup_controller.h"
 #import "chrome/browser/cocoa/menu_button.h"
@@ skipping 35 matching lines @@
 // object since it is called when the toolbar model changes.
 - (void)createActionButtonForExtension:(Extension*)extension
                              withIndex:(NSUInteger)index;
 // Removes an action button for the given extension from the container. This
 // method also does not affect the underlying toolbar model since it is called
 // when the toolbar model changes.
 - (void)removeActionButtonForExtension:(Extension*)extension;
 // Useful in the case of a Browser Action being added/removed from the middle of
 // the container, this method repositions each button according to the current
 // toolbar model.
-- (void)repositionActionButtons;
+- (void)repositionActionButtonsAndAnimate:(BOOL)animate;
 // During container resizing, buttons become more transparent as they are pushed
 // off the screen. This method updates each button's opacity determined by the
 // position of the button.
 - (void)updateButtonOpacity;
 // Returns the existing button with the given extension backing it; nil if it
 // cannot be found or the extension's ID is invalid.
 - (BrowserActionButton*)buttonForExtension:(Extension*)extension;
 // Returns the preferred width of the container given the number of visible
 // buttons |buttonCount|.
 - (CGFloat)containerWidthWithButtonCount:(NSUInteger)buttonCount;
@@ skipping 10 matching lines @@
 - (void)containerDragStart:(NSNotification*)notification;
 // Sends a notification for the toolbar to reposition surrounding UI elements.
 - (void)containerDragging:(NSNotification*)notification;
 // Determines which buttons need to be hidden based on the new size, hides them
 // and updates the chevron overflow menu. Also fires a notification to let the
 // toolbar know that the drag has finished.
 - (void)containerDragFinished:(NSNotification*)notification;
 // Updates the image associated with the button should it be within the chevron
 // menu.
 - (void)actionButtonUpdated:(NSNotification*)notification;
-
+// Adjusts the position of the surrounding action buttons depending on where the
+// button is within the container.
+- (void)actionButtonDragging:(NSNotification*)notification;
+// Updates the underlying toolbar model and "snaps" the button into its proper
+// place within the button grid.
+- (void)actionButtonDragFinished:(NSNotification*)notification;
+// Moves the given button both visually and within the toolbar model to the
+// specified index.
+- (void)moveButton:(BrowserActionButton*)button
+           toIndex:(NSUInteger)index
+           animate:(BOOL)animate;
 // Handles when the given BrowserActionButton object is clicked.
 - (void)browserActionClicked:(BrowserActionButton*)button;
 // Returns whether the given extension should be displayed. Only displays
 // incognito-enabled extensions in incognito mode. Otherwise returns YES.
 - (BOOL)shouldDisplayBrowserAction:(Extension*)extension;
 
 // The reason |frame| is specified in these chevron functions is because the
 // container may be animating and the end frame of the animation should be
 // passed instead of the current frame (which may be off and cause the chevron
 // to jump at the end of its animation).
@@ skipping 313 matching lines @@
 
   [buttons_ setObject:newButton forKey:buttonKey];
   if (index < [self containerButtonCapacity]) {
     [containerView_ addSubview:newButton];
   } else {
     [hiddenButtons_ addObject:newButton];
     [newButton setAlphaValue:0.0];
     [self updateOverflowMenu];
   }
 
-  [self repositionActionButtons];
+  [[NSNotificationCenter defaultCenter]
+      addObserver:self
+         selector:@selector(actionButtonDragging:)
+             name:kBrowserActionButtonDraggingNotification
+           object:newButton];
+  [[NSNotificationCenter defaultCenter]
+      addObserver:self
+         selector:@selector(actionButtonDragFinished:)
+             name:kBrowserActionButtonDragEndNotification
+           object:newButton];
+
+  [self repositionActionButtonsAndAnimate:NO];
   [containerView_ setMaxWidth:
       [self containerWidthWithButtonCount:[self buttonCount]]];
   [containerView_ setNeedsDisplay:YES];
 }
 
 - (void)removeActionButtonForExtension:(Extension*)extension {
   if (!extension->browser_action())
     return;
 
   NSString* buttonKey = base::SysUTF8ToNSString(extension->id());
@@ skipping 10 matching lines @@
   // It may or may not be hidden, but it won't matter to NSMutableArray either
   // way.
   [hiddenButtons_ removeObject:button];
   [self updateOverflowMenu];
 
   [buttons_ removeObjectForKey:buttonKey];
   if ([self buttonCount] == 0) {
     // No more buttons? Hide the container.
     [containerView_ setHidden:YES];
   } else {
-    [self repositionActionButtons];
+    [self repositionActionButtonsAndAnimate:NO];
   }
   [containerView_ setMaxWidth:
       [self containerWidthWithButtonCount:[self buttonCount]]];
   [containerView_ setNeedsDisplay:YES];
 }
 
-- (void)repositionActionButtons {
+- (void)repositionActionButtonsAndAnimate:(BOOL)animate {
   NSUInteger i = 0;
   for (ExtensionList::iterator iter = toolbarModel_->begin();
        iter != toolbarModel_->end(); ++iter) {
     if (![self shouldDisplayBrowserAction:*iter])
       continue;
-
-    CGFloat xOffset = kGrippyXOffset +
-        (i * (kBrowserActionWidth + kBrowserActionButtonPadding));
     BrowserActionButton* button = [self buttonForExtension:(*iter)];
     if (!button)
       continue;
-    NSRect buttonFrame = [button frame];
-    buttonFrame.origin.x = xOffset;
-    [button setFrame:buttonFrame];
+    if (![button isBeingDragged])
+      [self moveButton:button toIndex:i animate:animate];
     ++i;
   }
 }
 
 - (void)updateButtonOpacity {
   for (BrowserActionButton* button in [buttons_ allValues]) {
     NSRect buttonFrame = [button frame];
     buttonFrame.origin.x += kButtonOpacityLeadPadding;
     if (NSContainsRect([containerView_ bounds], buttonFrame)) {
       if ([button alphaValue] != 1.0)
@@ skipping 90 matching lines @@
   if (![hiddenButtons_ containsObject:button])
     return;
 
   // +1 item because of the title placeholder. See |updateOverflowMenu|.
   NSUInteger menuIndex = [hiddenButtons_ indexOfObject:button] + 1;
   NSMenuItem* item = [[chevronMenuButton_ attachedMenu] itemAtIndex:menuIndex];
   DCHECK(button == [item representedObject]);
   [item setImage:[button compositedImage]];
 }
 
+- (void)actionButtonDragging:(NSNotification*)notification {
+  if (![self chevronIsHidden])
+    [self setChevronHidden:YES inFrame:[containerView_ frame] animate:YES];
+
+  // Determine what index the dragged button should lie in, alter the model and
+  // reposition the buttons.
+  CGFloat dragThreshold = std::floor(kBrowserActionWidth / 2);
+  BrowserActionButton* draggedButton = [notification object];
+  NSRect draggedButtonFrame = [draggedButton frame];
+
+  NSUInteger index = 0;
+  for (ExtensionList::iterator iter = toolbarModel_->begin();
+       iter != toolbarModel_->end(); ++iter) {
+    BrowserActionButton* button = [self buttonForExtension:(*iter)];
+    CGFloat intersectionWidth =
+        NSWidth(NSIntersectionRect(draggedButtonFrame, [button frame]));
+
+    if (intersectionWidth > dragThreshold && button != draggedButton &&
+        ![button isAnimating]) {
+      toolbarModel_->MoveBrowserAction([draggedButton extension], index);
+      [self repositionActionButtonsAndAnimate:YES];
+      return;
+    }
+    ++index;
+  }
+}
+
+- (void)actionButtonDragFinished:(NSNotification*)notification {
+  [self showChevronIfNecessaryInFrame:[containerView_ frame] animate:YES];
+  DCHECK(![[notification object] isBeingDragged]);
+  [self repositionActionButtonsAndAnimate:YES];
+}
+
+- (void)moveButton:(BrowserActionButton*)button
+           toIndex:(NSUInteger)index
+           animate:(BOOL)animate {
+  CGFloat xOffset = kGrippyXOffset +
+      (index * (kBrowserActionWidth + kBrowserActionButtonPadding));
+  NSRect buttonFrame = [button frame];
+  buttonFrame.origin.x = xOffset;
+  [button setFrame:buttonFrame animate:animate];
+}
+
 - (void)browserActionClicked:(BrowserActionButton*)button {
   int tabId = [self currentTabId];
   if (tabId < 0) {
     NOTREACHED() << "No current tab.";
     return;
   }
 
   ExtensionAction* action = [button extension]->browser_action();
   if (action->HasPopup(tabId)) {
     NSPoint arrowPoint = [self popupPointForBrowserAction:[button extension]];
@@ skipping 62 matching lines @@
         NSViewAnimationFadeOutEffect, NSViewAnimationEffectKey,
         nil];
   } else {
     [chevronMenuButton_ setHidden:NO];
     animationDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
         chevronMenuButton_.get(), NSViewAnimationTargetKey,
         NSViewAnimationFadeInEffect, NSViewAnimationEffectKey,
         nil];
   }
   [chevronAnimation_ setViewAnimations:
-      [NSArray arrayWithObjects:animationDictionary, nil]];
+      [NSArray arrayWithObject:animationDictionary]];
   [chevronAnimation_ startAnimation];
 }
 
 - (void)chevronItemSelected:(id)menuItem {
   [self browserActionClicked:[menuItem representedObject]];
 }
 
 - (void)updateOverflowMenu {
   overflowMenu_.reset([[NSMenu alloc] initWithTitle:@""]);
   // See menu_button.h for documentation on why this is needed.
@@ skipping 29 matching lines @@
        iter != toolbarModel_->end(); ++iter) {
     if (i == index)
       return [buttons_ objectForKey:base::SysUTF8ToNSString((*iter)->id())];
 
     ++i;
   }
   return nil;
 }
 
 @end