// Copyright (c) 2009 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 "base/gfx/gtk_util.h"

#include <gdk/gdk.h>
#include <gtk/gtk.h>

#include "base/gfx/rect.h"
#include "skia/include/SkBitmap.h"

namespace {

// Callback used in RemoveAllChildren.
void RemoveWidget(GtkWidget* widget, gpointer container) {
  gtk_container_remove(GTK_CONTAINER(container), widget);
}

}  // namespace

namespace gfx {

const GdkColor kGdkWhite = GDK_COLOR_RGB(0xff, 0xff, 0xff);
const GdkColor kGdkBlack = GDK_COLOR_RGB(0x00, 0x00, 0x00);
const GdkColor kGdkGreen = GDK_COLOR_RGB(0x00, 0xff, 0x00);

void SubtractRectanglesFromRegion(GdkRegion* region,
                                  const std::vector<Rect>& cutouts) {
  for (size_t i = 0; i < cutouts.size(); ++i) {
    GdkRectangle rect = cutouts[i].ToGdkRectangle();
    GdkRegion* rect_region = gdk_region_rectangle(&rect);
    gdk_region_subtract(region, rect_region);
    // TODO(deanm): It would be nice to be able to reuse the GdkRegion here.
    gdk_region_destroy(rect_region);
  }
}

static void FreePixels(guchar* pixels, gpointer data) {
  free(data);
}

uint8_t* BGRAToRGBA(const uint8_t* pixels, int width, int height, int stride) {
  if (stride == 0)
    stride = width * 4;

  guchar* new_pixels = static_cast<guchar*>(malloc(height * stride));

  // We have to copy the pixels and swap from BGRA to RGBA.
  for (int i = 0; i < height; ++i) {
    for (int j = 0; j < width; ++j) {
      int idx = i * stride + j * 4;
      new_pixels[idx] = pixels[idx + 2];
      new_pixels[idx + 1] = pixels[idx + 1];
      new_pixels[idx + 2] = pixels[idx];
      new_pixels[idx + 3] = pixels[idx + 3];
    }
  }

  return new_pixels;
}

GdkPixbuf* GdkPixbufFromSkBitmap(const SkBitmap* bitmap) {
  bitmap->lockPixels();
  int width = bitmap->width();
  int height = bitmap->height();
  int stride = bitmap->rowBytes();
  const guchar* orig_data = static_cast<guchar*>(bitmap->getPixels());
  guchar* data = BGRAToRGBA(orig_data, width, height, stride);

  // This pixbuf takes ownership of our malloc()ed data and will
  // free it for us when it is destroyed.
  GdkPixbuf* pixbuf = gdk_pixbuf_new_from_data(
      data,
      GDK_COLORSPACE_RGB,  // The only colorspace gtk supports.
      true,  // There is an alpha channel.
      8,
      width, height, stride, &FreePixels, data);

  // Assume ownership of pixbuf.
  g_object_ref_sink(pixbuf);
  bitmap->unlockPixels();
  return pixbuf;
}

GtkWidget* CreateGtkBorderBin(GtkWidget* child, const GdkColor* color,
                              int top, int bottom, int left, int right) {
  // Use a GtkEventBox to get the background painted.  However, we can't just
  // use a container border, since it won't paint there.  Use an alignment
  // inside to get the sizes exactly of how we want the border painted.
  GtkWidget* ebox = gtk_event_box_new();
  gtk_widget_modify_bg(ebox, GTK_STATE_NORMAL, color);
  GtkWidget* alignment = gtk_alignment_new(0.0, 0.0, 1.0, 1.0);
  gtk_alignment_set_padding(GTK_ALIGNMENT(alignment), top, bottom, left, right);
  gtk_container_add(GTK_CONTAINER(alignment), child);
  gtk_container_add(GTK_CONTAINER(ebox), alignment);
  return ebox;
}

void RemoveAllChildren(GtkWidget* container) {
  gtk_container_foreach(GTK_CONTAINER(container), RemoveWidget, container);
}

}  // namespace gfx