| // Copyright 2014 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 "ui/views/corewm/cursor_height_provider_win.h" |
| |
| #include <windows.h> |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <algorithm> |
| #include <map> |
| #include <memory> |
| |
| #include "base/win/scoped_hdc.h" |
| |
| namespace { |
| using PixelData = std::unique_ptr<uint32_t[]>; |
| using HeightStorage = std::map<HCURSOR, int>; |
| |
| const uint32_t kBitsPeruint32 = sizeof(uint32_t) * 8; |
| // All bits are 1 for transparent portion of monochromatic mask. |
| const uint32_t kTransparentMask = 0xffffffff; |
| // This is height of default pointer arrow in Windows 7. |
| const int kDefaultHeight = 20; |
| // Masks are monochromatic. |
| const size_t kNumberOfColors = 2; |
| const size_t KHeaderAndPalette = |
| sizeof(BITMAPINFOHEADER) + kNumberOfColors * sizeof(RGBQUAD); |
| |
| HeightStorage* cached_heights = nullptr; |
| |
| // Extracts the pixel data of provided bitmap |
| PixelData GetBitmapData(HBITMAP handle, const BITMAPINFO& info, HDC hdc) { |
| PixelData data; |
| // Masks are monochromatic. |
| DCHECK_EQ(info.bmiHeader.biBitCount, 1); |
| if (info.bmiHeader.biBitCount != 1) |
| return data; |
| |
| // When getting pixel data palette is appended to memory pointed by |
| // BITMAPINFO passed so allocate additional memory to store additional data. |
| std::unique_ptr<char[]> header(new char[KHeaderAndPalette]); |
| memcpy(header.get(), &(info.bmiHeader), sizeof(info.bmiHeader)); |
| |
| data.reset(new uint32_t[info.bmiHeader.biSizeImage / sizeof(uint32_t)]); |
| |
| int result = GetDIBits(hdc, |
| handle, |
| 0, |
| info.bmiHeader.biHeight, |
| data.get(), |
| reinterpret_cast<BITMAPINFO*>(header.get()), |
| DIB_RGB_COLORS); |
| |
| if (result == 0) |
| data.reset(); |
| |
| return data; |
| } |
| |
| // Checks if the specifed row is transparent in provided bitmap. |
| bool IsRowTransparent(const PixelData& data, |
| const uint32_t row_size, |
| const uint32_t last_byte_mask, |
| const uint32_t y) { |
| // Set the padding bits to 1 to make mask matching easier. |
| *(data.get() + (y + 1) * row_size - 1) |= last_byte_mask; |
| for (uint32_t i = y * row_size; i < (y + 1) * row_size; ++i) { |
| if (*(data.get() + i) != kTransparentMask) |
| return false; |
| } |
| return true; |
| } |
| |
| // Gets the vertical offset between specified cursor's hotpoint and it's bottom. |
| // |
| // Gets the cursor image data and extract cursor's visible height. |
| // Based on that get's what should be the vertical offset between cursor's |
| // hot point and the tooltip. |
| int CalculateCursorHeight(HCURSOR cursor_handle) { |
| base::win::ScopedGetDC hdc(NULL); |
| |
| ICONINFO icon = {0}; |
| GetIconInfo(cursor_handle, &icon); |
| |
| BITMAPINFO bitmap_info = {}; |
| bitmap_info.bmiHeader.biSize = sizeof(bitmap_info.bmiHeader); |
| if (GetDIBits(hdc, icon.hbmMask, 0, 0, NULL, &bitmap_info, DIB_RGB_COLORS) == |
| 0) |
| return kDefaultHeight; |
| |
| // Rows are padded to full DWORDs. OR with this mask will set them to 1 |
| // to simplify matching with |transparent_mask|. |
| uint32_t last_byte_mask = 0xFFFFFFFF; |
| const unsigned char bits_to_shift = sizeof(last_byte_mask) * 8 - |
| (bitmap_info.bmiHeader.biWidth % kBitsPeruint32); |
| if (bits_to_shift != kBitsPeruint32) |
| last_byte_mask = (last_byte_mask << bits_to_shift); |
| else |
| last_byte_mask = 0; |
| |
| const uint32_t row_size = |
| (bitmap_info.bmiHeader.biWidth + kBitsPeruint32 - 1) / kBitsPeruint32; |
| PixelData data(GetBitmapData(icon.hbmMask, bitmap_info, hdc)); |
| if (data == NULL) |
| return kDefaultHeight; |
| |
| // There are 2 types of cursors: Ones that cover the area underneath |
| // completely (i.e. hand cursor) and ones that partially cover |
| // and partially blend with background (i. e. I-beam cursor). |
| // These will have either 1 square mask or 2 masks stacked on top |
| // of each other (xor mask and and mask). |
| const bool has_xor_mask = |
| bitmap_info.bmiHeader.biHeight == 2 * bitmap_info.bmiHeader.biWidth; |
| const int cursor_height = |
| has_xor_mask ? static_cast<int>(bitmap_info.bmiHeader.biHeight / 2) |
| : static_cast<int>(bitmap_info.bmiHeader.biHeight); |
| int xor_offset; |
| if (has_xor_mask) { |
| for (xor_offset = 0; xor_offset < cursor_height; ++xor_offset) { |
| const uint32_t row_start = row_size * xor_offset; |
| const uint32_t row_boundary = row_start + row_size; |
| for (uint32_t i = row_start; i < row_boundary; ++i) |
| data.get()[i] = ~(data.get()[i]); |
| if (!IsRowTransparent(data, row_size, last_byte_mask, xor_offset)) { |
| break; |
| } |
| } |
| } else { |
| xor_offset = cursor_height; |
| } |
| |
| int and_offset; |
| |
| for (and_offset = has_xor_mask ? cursor_height : 0; |
| and_offset < bitmap_info.bmiHeader.biHeight; ++and_offset) { |
| if (!IsRowTransparent(data, row_size, last_byte_mask, and_offset)) { |
| break; |
| } |
| } |
| if (has_xor_mask) { |
| and_offset -= cursor_height; |
| } |
| const int offset = std::min(xor_offset, and_offset); |
| |
| DeleteObject(icon.hbmColor); |
| DeleteObject(icon.hbmMask); |
| |
| return cursor_height - offset - icon.yHotspot + 1; |
| } |
| |
| } // namespace |
| |
| namespace views { |
| namespace corewm { |
| |
| int GetCurrentCursorVisibleHeight() { |
| CURSORINFO cursor = {0}; |
| cursor.cbSize = sizeof(cursor); |
| GetCursorInfo(&cursor); |
| |
| if (cached_heights == NULL) |
| cached_heights = new HeightStorage; |
| |
| HeightStorage::const_iterator cached_height = |
| cached_heights->find(cursor.hCursor); |
| if (cached_height != cached_heights->end()) |
| return cached_height->second; |
| |
| const int height = CalculateCursorHeight(cursor.hCursor); |
| (*cached_heights)[cursor.hCursor] = height; |
| |
| return height; |
| } |
| |
| } // namespace corewm |
| } // namespace views |