chrome/browser/ui/views/frame/windows_icon_painter.cc

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/views/frame/windows_icon_painter.h"

#include "base/numerics/safe_conversions.h"
#include "chrome/browser/ui/color/chrome_color_id.h"
#include "ui/gfx/color_utils.h"
#include "ui/gfx/geometry/rect_conversions.h"
#include "ui/gfx/geometry/skia_conversions.h"
#include "ui/gfx/scoped_canvas.h"

namespace {

// Canvas::DrawRect's stroke can bleed out of |rect|'s bounds, so this draws a
// rectangle inset such that the result is constrained to |rect|'s size.
void DrawRect(gfx::Canvas* canvas,
              const gfx::Rect& rect,
              const cc::PaintFlags& flags) {
  gfx::RectF rect_f(rect);
  float stroke_half_width = flags.getStrokeWidth() / 2;
  rect_f.Inset(stroke_half_width);
  canvas->DrawRect(rect_f, flags);
}

void DrawRoundRect(gfx::Canvas* canvas,
                   const gfx::Rect& rect,
                   float radius,
                   const cc::PaintFlags& flags) {
  gfx::RectF rect_f(rect);
  float stroke_half_width = flags.getStrokeWidth() / 2;
  rect_f.Inset(stroke_half_width);
  canvas->DrawRoundRect(rect_f, radius, flags);
}

// Draws a path containing the top and right edges of a rounded rectangle.
void DrawRoundRectEdges(gfx::Canvas* canvas,
                        const gfx::Rect& rect,
                        float radius,
                        const cc::PaintFlags& flags) {
  gfx::RectF symbol_rect_f(rect);
  float stroke_half_width = flags.getStrokeWidth() / 2;
  symbol_rect_f.Inset(stroke_half_width);
  SkPath path;
  path.moveTo(symbol_rect_f.x(), symbol_rect_f.y());
  path.arcTo(symbol_rect_f.right(), symbol_rect_f.y(), symbol_rect_f.right(),
             symbol_rect_f.y() + radius, radius);
  path.lineTo(symbol_rect_f.right(), symbol_rect_f.bottom());
  canvas->DrawPath(path, flags);
}

}  // namespace

Windows10IconPainter::Windows10IconPainter() = default;
Windows10IconPainter::~Windows10IconPainter() = default;

void Windows10IconPainter::PaintMinimizeIcon(gfx::Canvas* canvas,
                                             gfx::Rect& symbol_rect,
                                             cc::PaintFlags& flags) {
  const int y = symbol_rect.CenterPoint().y();
  const gfx::Point p1 = gfx::Point(symbol_rect.x(), y);
  const gfx::Point p2 = gfx::Point(symbol_rect.right(), y);
  canvas->DrawLine(p1, p2, flags);
}

void Windows10IconPainter::PaintMaximizeIcon(gfx::Canvas* canvas,
                                             gfx::Rect& symbol_rect,
                                             cc::PaintFlags& flags) {
  DrawRect(canvas, symbol_rect, flags);
}

void Windows10IconPainter::PaintRestoreIcon(gfx::Canvas* canvas,
                                            gfx::Rect& symbol_rect,
                                            cc::PaintFlags& flags) {
  const int separation = base::ClampFloor(2 * canvas->image_scale());
  symbol_rect.Inset(gfx::Insets::TLBR(separation, 0, 0, separation));

  // Bottom left ("in front") square.
  DrawRect(canvas, symbol_rect, flags);

  // Top right ("behind") square.
  canvas->ClipRect(symbol_rect, SkClipOp::kDifference);
  symbol_rect.Offset(separation, -separation);
  DrawRect(canvas, symbol_rect, flags);
}

void Windows10IconPainter::PaintCloseIcon(gfx::Canvas* canvas,
                                          gfx::Rect& symbol_rect,
                                          cc::PaintFlags& flags) {
  // TODO(bsep): This sometimes draws misaligned at fractional device scales
  // because the button's origin isn't necessarily aligned to pixels.
  flags.setAntiAlias(true);
  canvas->ClipRect(symbol_rect);
  SkPath path;
  path.moveTo(symbol_rect.x(), symbol_rect.y());
  path.lineTo(symbol_rect.right(), symbol_rect.bottom());
  path.moveTo(symbol_rect.right(), symbol_rect.y());
  path.lineTo(symbol_rect.x(), symbol_rect.bottom());
  canvas->DrawPath(path, flags);
}

void Windows10IconPainter::PaintTabSearchIcon(gfx::Canvas* canvas,
                                              gfx::Rect& symbol_rect,
                                              cc::PaintFlags& flags) {
  flags.setAntiAlias(true);
  canvas->ClipRect(symbol_rect);
  // The chevron should occupy the space between the upper and lower quarter
  // of the `symbol_rect` bounds.
  symbol_rect.Inset(gfx::Insets::VH(symbol_rect.height() / 4, 0));
  SkPath path;
  path.moveTo(gfx::PointToSkPoint(symbol_rect.origin()));
  path.lineTo(gfx::PointToSkPoint(symbol_rect.bottom_center()));
  path.lineTo(gfx::PointToSkPoint(symbol_rect.top_right()));
  canvas->DrawPath(path, flags);
}

Windows11IconPainter::Windows11IconPainter() = default;
Windows11IconPainter::~Windows11IconPainter() = default;

void Windows11IconPainter::PaintMaximizeIcon(gfx::Canvas* canvas,
                                             gfx::Rect& symbol_rect,
                                             cc::PaintFlags& flags) {
  flags.setAntiAlias(true);
  const float corner_radius = canvas->image_scale();
  DrawRoundRect(canvas, symbol_rect, corner_radius, flags);
}

void Windows11IconPainter::PaintRestoreIcon(gfx::Canvas* canvas,
                                            gfx::Rect& symbol_rect,
                                            cc::PaintFlags& flags) {
  const int separation = base::ClampFloor(2 * canvas->image_scale());
  symbol_rect.Inset(gfx::Insets::TLBR(separation, 0, 0, separation));

  flags.setAntiAlias(true);
  // Bottom left ("in front") rounded square.
  const float bottom_rect_radius = canvas->image_scale();
  DrawRoundRect(canvas, symbol_rect, bottom_rect_radius, flags);

  // Top right ("behind") top+right edges of rounded square (2.5x).
  symbol_rect.Offset(separation, -separation);

  const float top_rect_radius = 2.5f * canvas->image_scale();
  DrawRoundRectEdges(canvas, symbol_rect, top_rect_radius, flags);
}