ipc/chromium/src/base/base_drop_target.h@6474c204b198 (annotated)
ipc/chromium/src/base/base_drop_target.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. |
| michael@0 | 2 | // Use of this source code is governed by a BSD-style license that can be |
| michael@0 | 3 | // found in the LICENSE file. |
| michael@0 | 4 | |
| michael@0 | 5 | #ifndef BASE_BASE_DROP_TARGET_H_ |
| michael@0 | 6 | #define BASE_BASE_DROP_TARGET_H_ |
| michael@0 | 7 | |
| michael@0 | 8 | #include <objidl.h> |
| michael@0 | 9 | |
| michael@0 | 10 | #include "base/ref_counted.h" |
| michael@0 | 11 | |
| michael@0 | 12 | struct IDropTargetHelper; |
| michael@0 | 13 | |
| michael@0 | 14 | // A DropTarget implementation that takes care of the nitty gritty |
| michael@0 | 15 | // of dnd. While this class is concrete, subclasses will most likely |
| michael@0 | 16 | // want to override various OnXXX methods. |
| michael@0 | 17 | // |
| michael@0 | 18 | // Because BaseDropTarget is ref counted you shouldn't delete it directly, |
| michael@0 | 19 | // rather wrap it in a scoped_refptr. Be sure and invoke RevokeDragDrop(m_hWnd) |
| michael@0 | 20 | // before the HWND is deleted too. |
| michael@0 | 21 | // |
| michael@0 | 22 | // This class is meant to be used in a STA and is not multithread-safe. |
| michael@0 | 23 | class BaseDropTarget : public IDropTarget { |
| michael@0 | 24 | public: |
| michael@0 | 25 | // Create a new BaseDropTarget associating it with the given HWND. |
| michael@0 | 26 | explicit BaseDropTarget(HWND hwnd); |
| michael@0 | 27 | virtual ~BaseDropTarget(); |
| michael@0 | 28 | |
| michael@0 | 29 | // When suspend is set to |true|, the drop target does not receive drops from |
| michael@0 | 30 | // drags initiated within the owning HWND. |
| michael@0 | 31 | // TODO(beng): (http://b/1085385) figure out how we will handle legitimate |
| michael@0 | 32 | // drag-drop operations within the same HWND, such as dragging |
| michael@0 | 33 | // selected text to an edit field. |
| michael@0 | 34 | void set_suspend(bool suspend) { suspend_ = suspend; } |
| michael@0 | 35 | |
| michael@0 | 36 | // IDropTarget implementation: |
| michael@0 | 37 | HRESULT __stdcall DragEnter(IDataObject* data_object, |
| michael@0 | 38 | DWORD key_state, |
| michael@0 | 39 | POINTL cursor_position, |
| michael@0 | 40 | DWORD* effect); |
| michael@0 | 41 | HRESULT __stdcall DragOver(DWORD key_state, |
| michael@0 | 42 | POINTL cursor_position, |
| michael@0 | 43 | DWORD* effect); |
| michael@0 | 44 | HRESULT __stdcall DragLeave(); |
| michael@0 | 45 | HRESULT __stdcall Drop(IDataObject* data_object, |
| michael@0 | 46 | DWORD key_state, |
| michael@0 | 47 | POINTL cursor_position, |
| michael@0 | 48 | DWORD* effect); |
| michael@0 | 49 | |
| michael@0 | 50 | // IUnknown implementation: |
| michael@0 | 51 | HRESULT __stdcall QueryInterface(const IID& iid, void** object); |
| michael@0 | 52 | ULONG __stdcall AddRef(); |
| michael@0 | 53 | ULONG __stdcall Release(); |
| michael@0 | 54 | |
| michael@0 | 55 | protected: |
| michael@0 | 56 | // Returns the hosting HWND. |
| michael@0 | 57 | HWND GetHWND() { return hwnd_; } |
| michael@0 | 58 | |
| michael@0 | 59 | // Invoked when the cursor first moves over the hwnd during a dnd session. |
| michael@0 | 60 | // This should return a bitmask of the supported drop operations: |
| michael@0 | 61 | // DROPEFFECT_NONE, DROPEFFECT_COPY, DROPEFFECT_LINK and/or |
| michael@0 | 62 | // DROPEFFECT_MOVE. |
| michael@0 | 63 | virtual DWORD OnDragEnter(IDataObject* data_object, |
| michael@0 | 64 | DWORD key_state, |
| michael@0 | 65 | POINT cursor_position, |
| michael@0 | 66 | DWORD effect); |
| michael@0 | 67 | |
| michael@0 | 68 | // Invoked when the cursor moves over the window during a dnd session. |
| michael@0 | 69 | // This should return a bitmask of the supported drop operations: |
| michael@0 | 70 | // DROPEFFECT_NONE, DROPEFFECT_COPY, DROPEFFECT_LINK and/or |
| michael@0 | 71 | // DROPEFFECT_MOVE. |
| michael@0 | 72 | virtual DWORD OnDragOver(IDataObject* data_object, |
| michael@0 | 73 | DWORD key_state, |
| michael@0 | 74 | POINT cursor_position, |
| michael@0 | 75 | DWORD effect); |
| michael@0 | 76 | |
| michael@0 | 77 | // Invoked when the cursor moves outside the bounds of the hwnd during a |
| michael@0 | 78 | // dnd session. |
| michael@0 | 79 | virtual void OnDragLeave(IDataObject* data_object); |
| michael@0 | 80 | |
| michael@0 | 81 | // Invoked when the drop ends on the window. This should return the operation |
| michael@0 | 82 | // that was taken. |
| michael@0 | 83 | virtual DWORD OnDrop(IDataObject* data_object, |
| michael@0 | 84 | DWORD key_state, |
| michael@0 | 85 | POINT cursor_position, |
| michael@0 | 86 | DWORD effect); |
| michael@0 | 87 | |
| michael@0 | 88 | // Return the drag identity. |
| michael@0 | 89 | static int32_t GetDragIdentity() { return drag_identity_; } |
| michael@0 | 90 | |
| michael@0 | 91 | private: |
| michael@0 | 92 | // Returns the cached drop helper, creating one if necessary. The returned |
| michael@0 | 93 | // object is not addrefed. May return NULL if the object couldn't be created. |
| michael@0 | 94 | static IDropTargetHelper* DropHelper(); |
| michael@0 | 95 | |
| michael@0 | 96 | // The data object currently being dragged over this drop target. |
| michael@0 | 97 | scoped_refptr<IDataObject> current_data_object_; |
| michael@0 | 98 | |
| michael@0 | 99 | // A helper object that is used to provide drag image support while the mouse |
| michael@0 | 100 | // is dragging over the content area. |
| michael@0 | 101 | // |
| michael@0 | 102 | // DO NOT ACCESS DIRECTLY! Use DropHelper() instead, which will lazily create |
| michael@0 | 103 | // this if it doesn't exist yet. This object can take tens of milliseconds to |
| michael@0 | 104 | // create, and we don't want to block any window opening for this, especially |
| michael@0 | 105 | // since often, DnD will never be used. Instead, we force this penalty to the |
| michael@0 | 106 | // first time it is actually used. |
| michael@0 | 107 | static IDropTargetHelper* cached_drop_target_helper_; |
| michael@0 | 108 | |
| michael@0 | 109 | // The drag identity (id). An up-counter that increases when the cursor first |
| michael@0 | 110 | // moves over the HWND in a DnD session (OnDragEnter). 0 is reserved to mean |
| michael@0 | 111 | // the "no/unknown" identity, and is used for initialization. The identity is |
| michael@0 | 112 | // sent to the renderer in drag enter notifications. Note: the identity value |
| michael@0 | 113 | // is passed over the renderer NPAPI interface to gears, so use int32_t instead |
| michael@0 | 114 | // of int here. |
| michael@0 | 115 | static int32_t drag_identity_; |
| michael@0 | 116 | |
| michael@0 | 117 | // The HWND of the source. This HWND is used to determine coordinates for |
| michael@0 | 118 | // mouse events that are sent to the renderer notifying various drag states. |
| michael@0 | 119 | HWND hwnd_; |
| michael@0 | 120 | |
| michael@0 | 121 | // Whether or not we are currently processing drag notifications for drags |
| michael@0 | 122 | // initiated in this window. |
| michael@0 | 123 | bool suspend_; |
| michael@0 | 124 | |
| michael@0 | 125 | LONG ref_count_; |
| michael@0 | 126 | |
| michael@0 | 127 | DISALLOW_EVIL_CONSTRUCTORS(BaseDropTarget); |
| michael@0 | 128 | }; |
| michael@0 | 129 | |
| michael@0 | 130 | #endif // BASE_BASE_DROP_TARGET_H_ |
