mac: Makeshift UI for scroll feedback.

chrome/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/renderer_host/render_widget_host_view_mac.h"
 
 #include <QuartzCore/QuartzCore.h>
 
 #include <cmath>
 
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #import "base/mac/scoped_nsautorelease_pool.h"
 #include "base/metrics/histogram.h"
 #import "base/memory/scoped_nsobject.h"
 #include "base/string_util.h"
 #include "base/sys_info.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/browser_trial.h"
 #include "chrome/browser/mac/closure_blocks_leopard_compat.h"
 #import "chrome/browser/renderer_host/accelerated_plugin_view_mac.h"
 #import "chrome/browser/renderer_host/text_input_client_mac.h"
 #include "chrome/browser/spellchecker/spellchecker_platform_engine.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
+#import "chrome/browser/ui/cocoa/history_overlay_controller.h"
 #import "chrome/browser/ui/cocoa/rwhvm_editcommand_helper.h"
 #import "chrome/browser/ui/cocoa/view_id_util.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/spellcheck_messages.h"
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 #include "content/browser/browser_thread.h"
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
 #include "content/browser/plugin_process_host.h"
 #include "content/browser/renderer_host/backing_store_mac.h"
@@ skipping 1544 matching lines @@
         // the left in the same gesture, that should trigger history
         // immediately if there's no scrollbar, hence the check for
         // hasHorizontalScrollbar_.
         (!hasHorizontalScrollbar_ ||
         // One would think we have to check canGoBack / canGoForward here, but
         // that's actually done in the renderer
         // (ChromeClientImpl::shouldRubberBand()), when it decides if it should
         // rubberband or send back an event unhandled.
             (isPinnedLeft_ && !isRightScroll) ||
             (isPinnedRight_ && isRightScroll))) {
+
+      // Released by the tracking handler once the gesture is complete.
+      HistoryOverlayController* historyOverlay =
+          [[HistoryOverlayController alloc]
+            initForMode:goForward ? kHistoryOverlayModeForward :
+                                    kHistoryOverlayModeBack];
+
       // The way this api works: gestureAmount is between -1 and 1 (float). If
       // the user does the gesture for more than about 25% (i.e. < -0.25 or >
       // 0.25) and then lets go, it is accepted, we get a NSEventPhaseEnded,
       // and after that the block is called with amounts animating towards 1
       // (or -1, depending on the direction).  If the user lets go below that
       // threshold, we get NSEventPhaseCancelled, and the amount animates
       // toward 0.

[Mark Mentovai, 2011/08/16 01:01:20]

Since you describe the API here and isComplete is now significant, can you
expand on this comment slightly to indicate when the block gets called with
isComplete YES?

[Nico, 2011/08/16 04:56:17]

Done.

       [theEvent trackSwipeEventWithOptions:0
                   dampenAmountThresholdMin:-1
                                        max:1
                               usingHandler:^(CGFloat gestureAmount,
                                              NSEventPhase phase,
                                              BOOL isComplete,
                                              BOOL *stop) {
+          if (phase == NSEventPhaseBegan) {
+            [historyOverlay showPanelForWindow:[self window]];
+            return;
+          }
+
           // |gestureAmount| obeys -[NSEvent isDirectionInvertedFromDevice]
           // automatically.
-          // TODO(thakis): UI.
           Browser* browser = BrowserList::GetLastActive();
           if (phase == NSEventPhaseEnded && browser) {
             if (goForward)
               browser->GoForward(CURRENT_TAB);
             else
               browser->GoBack(CURRENT_TAB);
           }
+
+          [historyOverlay setProgress:gestureAmount];
+          if (isComplete) {
+            [historyOverlay dismiss];
+            [historyOverlay release];
+          }
         }];
       return YES;
     }
   }
   return NO;
 }
 
 - (void)scrollWheel:(NSEvent*)theEvent {
   [self cancelChildPopups];
 
@@ skipping 1261 matching lines @@
   if (!string) return NO;
 
   // If the user is currently using an IME, confirm the IME input,
   // and then insert the text from the service, the same as TextEdit and Safari.
   [self confirmComposition];
   [self insertText:string];
   return YES;
 }
 
 @end