| // Copyright 2008, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include <windows.h> |
| #include <shlobj.h> |
| |
| #include "base/base_drop_target.h" |
| |
| #include "base/logging.h" |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| IDropTargetHelper* BaseDropTarget::cached_drop_target_helper_ = NULL; |
| |
| BaseDropTarget::BaseDropTarget(HWND hwnd) |
| : suspend_(false), |
| ref_count_(0), |
| hwnd_(hwnd) { |
| DCHECK(hwnd); |
| HRESULT result = RegisterDragDrop(hwnd, this); |
| } |
| |
| BaseDropTarget::~BaseDropTarget() { |
| } |
| |
| // static |
| IDropTargetHelper* BaseDropTarget::DropHelper() { |
| if (!cached_drop_target_helper_) { |
| CoCreateInstance(CLSID_DragDropHelper, 0, CLSCTX_INPROC_SERVER, |
| IID_IDropTargetHelper, |
| reinterpret_cast<void**>(&cached_drop_target_helper_)); |
| } |
| return cached_drop_target_helper_; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // BaseDropTarget, IDropTarget implementation: |
| |
| HRESULT BaseDropTarget::DragEnter(IDataObject* data_object, |
| DWORD key_state, |
| POINTL cursor_position, |
| DWORD* effect) { |
| // Tell the helper that we entered so it can update the drag image. |
| IDropTargetHelper* drop_helper = DropHelper(); |
| if (drop_helper) { |
| drop_helper->DragEnter(GetHWND(), data_object, |
| reinterpret_cast<POINT*>(&cursor_position), *effect); |
| } |
| |
| // You can't drag and drop within the same HWND. |
| if (suspend_) { |
| *effect = DROPEFFECT_NONE; |
| return S_OK; |
| } |
| current_data_object_ = data_object; |
| POINT screen_pt = { cursor_position.x, cursor_position.y }; |
| *effect = OnDragEnter(current_data_object_, key_state, screen_pt, *effect); |
| return S_OK; |
| } |
| |
| HRESULT BaseDropTarget::DragOver(DWORD key_state, |
| POINTL cursor_position, |
| DWORD* effect) { |
| // Tell the helper that we moved over it so it can update the drag image. |
| IDropTargetHelper* drop_helper = DropHelper(); |
| if (drop_helper) |
| drop_helper->DragOver(reinterpret_cast<POINT*>(&cursor_position), *effect); |
| |
| if (suspend_) { |
| *effect = DROPEFFECT_NONE; |
| return S_OK; |
| } |
| |
| POINT screen_pt = { cursor_position.x, cursor_position.y }; |
| *effect = OnDragOver(current_data_object_, key_state, screen_pt, *effect); |
| return S_OK; |
| } |
| |
| HRESULT BaseDropTarget::DragLeave() { |
| // Tell the helper that we moved out of it so it can update the drag image. |
| IDropTargetHelper* drop_helper = DropHelper(); |
| if (drop_helper) |
| drop_helper->DragLeave(); |
| |
| OnDragLeave(current_data_object_); |
| |
| current_data_object_ = NULL; |
| return S_OK; |
| } |
| |
| HRESULT BaseDropTarget::Drop(IDataObject* data_object, |
| DWORD key_state, |
| POINTL cursor_position, |
| DWORD* effect) { |
| // Tell the helper that we dropped onto it so it can update the drag image. |
| IDropTargetHelper* drop_helper = DropHelper(); |
| if (drop_helper) { |
| drop_helper->Drop(current_data_object_, |
| reinterpret_cast<POINT*>(&cursor_position), *effect); |
| } |
| |
| if (suspend_) { |
| *effect = DROPEFFECT_NONE; |
| return S_OK; |
| } |
| |
| POINT screen_pt = { cursor_position.x, cursor_position.y }; |
| *effect = OnDrop(current_data_object_, key_state, screen_pt, *effect); |
| return S_OK; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // BaseDropTarget, IUnknown implementation: |
| |
| HRESULT BaseDropTarget::QueryInterface(const IID& iid, void** object) { |
| *object = NULL; |
| if (IsEqualIID(iid, IID_IUnknown) || IsEqualIID(iid, IID_IDropTarget)) { |
| *object = this; |
| } else { |
| return E_NOINTERFACE; |
| } |
| AddRef(); |
| return S_OK; |
| } |
| |
| ULONG BaseDropTarget::AddRef() { |
| return InterlockedIncrement(&ref_count_); |
| } |
| |
| ULONG BaseDropTarget::Release() { |
| if (InterlockedDecrement(&ref_count_) == 0) { |
| ULONG copied_refcnt = ref_count_; |
| delete this; |
| return copied_refcnt; |
| } |
| return ref_count_; |
| } |
| |
| DWORD BaseDropTarget::OnDragEnter(IDataObject* data_object, |
| DWORD key_state, |
| POINT cursor_position, |
| DWORD effect) { |
| return DROPEFFECT_NONE; |
| } |
| |
| DWORD BaseDropTarget::OnDragOver(IDataObject* data_object, |
| DWORD key_state, |
| POINT cursor_position, |
| DWORD effect) { |
| return DROPEFFECT_NONE; |
| } |
| |
| void BaseDropTarget::OnDragLeave(IDataObject* data_object) { |
| } |
| |
| DWORD BaseDropTarget::OnDrop(IDataObject* data_object, |
| DWORD key_state, |
| POINT cursor_position, |
| DWORD effect) { |
| return DROPEFFECT_NONE; |
| } |