ui/platform_window/x11/x11_cursor_ozone.cc

// Copyright 2016 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/platform_window/x11/x11_cursor_ozone.h"

#include <X11/Xcursor/Xcursor.h>
#include <X11/Xlib.h>

#include "base/logging.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "ui/base/x/x11_util.h"
#include "ui/gfx/geometry/point.h"

namespace ui {

namespace {

// Converts a SKBitmap to unpremul alpha.
SkBitmap ConvertSkBitmapToUnpremul(const SkBitmap& bitmap) {
  DCHECK_NE(bitmap.alphaType(), kUnpremul_SkAlphaType);

  SkImageInfo image_info = SkImageInfo::MakeN32(bitmap.width(), bitmap.height(),
                                                kUnpremul_SkAlphaType);
  SkBitmap converted_bitmap;
  converted_bitmap.allocPixels(image_info);
  bitmap.readPixels(image_info, converted_bitmap.getPixels(),
                    image_info.minRowBytes(), 0, 0);

  return converted_bitmap;
}

// Creates an XCursorImage for cursor bitmap.
XcursorImage* CreateXCursorImage(const SkBitmap& bitmap,
                                 const gfx::Point& hotspot) {
  // X11 expects bitmap with unpremul alpha. If bitmap is premul then convert,
  // otherwise semi-transparent parts of cursor will look strange.
  if (bitmap.alphaType() != kUnpremul_SkAlphaType) {
    SkBitmap converted_bitmap = ConvertSkBitmapToUnpremul(bitmap);
    return SkBitmapToXcursorImage(&converted_bitmap, hotspot);
  } else {
    return SkBitmapToXcursorImage(&bitmap, hotspot);
  }
}

}  // namespace

X11CursorOzone::X11CursorOzone(const SkBitmap& bitmap,
                               const gfx::Point& hotspot) {
  XcursorImage* image = CreateXCursorImage(bitmap, hotspot);
  xcursor_ = XcursorImageLoadCursor(gfx::GetXDisplay(), image);
  XcursorImageDestroy(image);
}

X11CursorOzone::X11CursorOzone(const std::vector<SkBitmap>& bitmaps,
                               const gfx::Point& hotspot,
                               int frame_delay_ms) {
  // Initialize an XCursorImage for each frame, store all of them in
  // XCursorImages and load the cursor from that.
  XcursorImages* images = XcursorImagesCreate(bitmaps.size());
  images->nimage = bitmaps.size();
  for (size_t frame = 0; frame < bitmaps.size(); ++frame) {
    XcursorImage* x_image = CreateXCursorImage(bitmaps[frame], hotspot);
    x_image->delay = frame_delay_ms;
    images->images[frame] = x_image;
  }

  xcursor_ = XcursorImagesLoadCursor(gfx::GetXDisplay(), images);
  XcursorImagesDestroy(images);
}

scoped_refptr<X11CursorOzone> X11CursorOzone::CreateInvisible() {
  scoped_refptr<X11CursorOzone> invisible_ = new X11CursorOzone();
  invisible_->xcursor_ = CreateInvisibleCursor();
  return invisible_;
}

X11CursorOzone::X11CursorOzone() {}

X11CursorOzone::~X11CursorOzone() {
  XFreeCursor(gfx::GetXDisplay(), xcursor_);
}

}  // namespace ui