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// Copyright (c) 2012 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.
#ifndef CONTENT_BROWSER_RENDERER_HOST_TEXT_INPUT_CLIENT_MAC_H_
#define CONTENT_BROWSER_RENDERER_HOST_TEXT_INPUT_CLIENT_MAC_H_
#import <Cocoa/Cocoa.h>
#include "base/mac/scoped_block.h"
#include "base/mac/scoped_nsobject.h"
#include "base/synchronization/condition_variable.h"
#include "base/synchronization/lock.h"
#include "content/common/content_export.h"
#include "ui/gfx/geometry/point.h"
template <typename T> struct DefaultSingletonTraits;
namespace content {
class RenderWidgetHost;
// This class helps with the Mac OS X dictionary popup. For the design overview,
// look at this document:
// http://dev.chromium.org/developers/design-documents/system-dictionary-pop-up-architecture
//
// This service is used to marshall information for these three methods that are
// implemented in RenderWidgetHostViewMac:
// -[NSTextInput characterIndexForPoint:]
// -[NSTextInput attributedSubstringFromRange:]
// -[NSTextInput firstRectForCharacterRange:]
//
// Because these methods are part of a synchronous system API, implementing them
// requires getting information from the renderer synchronously. Rather than
// using an actual sync IPC message, a normal async ViewMsg is used with a lock
// and condition (managed by this service).
//
// Mac OS 10.8 introduced -[NSResponder quickLookWithEvent:].
// We can use it to implement asynchronous dictionary lookup when the user
// taps a word using three fingers.
// But currently the "Look Up in Dictionary" context menu item still goes
// through the above synchronous IPC.
class CONTENT_EXPORT TextInputClientMac {
public:
// Returns the singleton instance.
static TextInputClientMac* GetInstance();
// Each of the three methods mentioned above has an associated pair of methods
// to get data from the renderer. The Get*() methods block the calling thread
// (always the UI thread) with a short timeout after the async message has
// been sent to the renderer to lookup the information needed to respond to
// the system. The Set*AndSignal() methods store the looked up information in
// this service and signal the condition to allow the Get*() methods to
// unlock and return that stored value.
//
// Returns NSNotFound if the request times out or is not completed.
NSUInteger GetCharacterIndexAtPoint(RenderWidgetHost* rwh, gfx::Point point);
// Returns nil if the request times out or is completed.
NSAttributedString* GetAttributedSubstringFromRange(
RenderWidgetHost* rwh, NSRange range);
// Returns NSZeroRect if the request times out or is not completed. The result
// is in WebKit coordinates.
NSRect GetFirstRectForRange(RenderWidgetHost* rwh, NSRange range);
// When the renderer sends the ViewHostMsg reply, the RenderMessageFilter will
// call the corresponding method on the IO thread to unlock the condition and
// allow the Get*() methods to continue/return.
void SetCharacterIndexAndSignal(NSUInteger index);
void SetFirstRectAndSignal(NSRect first_rect);
void SetSubstringAndSignal(NSAttributedString* string);
// This async method is invoked from RenderWidgetHostViewCocoa's
// -quickLookWithEvent:, when the user taps a word using 3 fingers.
// The reply callback will be invoked from the IO thread, the caller is
// responsible for bouncing to the main thread if necessary.
// The callback parameters provide the attributed word under the point and
// the lower left baseline point of the text.
void GetStringAtPoint(RenderWidgetHost* rwh,
gfx::Point point,
void (^replyHandler)(NSAttributedString*, NSPoint));
// This is called on the IO thread when we get the renderer's reply for
// GetStringAtPoint.
void GetStringAtPointReply(NSAttributedString*, NSPoint);
private:
friend struct DefaultSingletonTraits<TextInputClientMac>;
TextInputClientMac();
~TextInputClientMac();
// The critical sections that the Condition guards are in Get*() methods.
// These methods lock the internal condition for use before the asynchronous
// message is sent to the renderer to lookup the required information. These
// are only used on the UI thread.
void BeforeRequest();
// Called at the end of a critical section. This will release the lock and
// condition.
void AfterRequest();
NSUInteger character_index_;
NSRect first_rect_;
base::scoped_nsobject<NSAttributedString> substring_;
base::Lock lock_;
base::ConditionVariable condition_;
base::mac::ScopedBlock<void(^)(NSAttributedString*, NSPoint)> replyHandler_;
DISALLOW_COPY_AND_ASSIGN(TextInputClientMac);
};
} // namespace content
#endif // CONTENT_BROWSER_RENDERER_HOST_TEXT_INPUT_CLIENT_MAC_H_