// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif
#include "chrome/browser/ui/views/frame/minimize_button_metrics_win.h"
#include <dwmapi.h>
#include "base/check.h"
#include "base/i18n/rtl.h"
#include "ui/display/win/screen_win.h"
#include "ui/gfx/geometry/point.h"
namespace {
const int kButtonBoundsPositionOffset = 6;
const int kInvalidOffset = static_cast<int>(0x80000000);
using display::win::ScreenWin;
} // namespace
// static
int MinimizeButtonMetrics::last_cached_minimize_button_x_delta_ = 0;
// static
int MinimizeButtonMetrics::button_bounds_position_offset_ = kInvalidOffset;
MinimizeButtonMetrics::MinimizeButtonMetrics() = default;
MinimizeButtonMetrics::~MinimizeButtonMetrics() = default;
void MinimizeButtonMetrics::Init(HWND hwnd) {
DCHECK(!hwnd_);
hwnd_ = hwnd;
}
void MinimizeButtonMetrics::OnHWNDActivated() {
was_activated_ = true;
// NOTE: we don't cache here as it seems only after the activate is the value
// correct.
}
void MinimizeButtonMetrics::OnDpiChanged() {
// This ensures that the next time GetMinimizeButtonOffsetX() is called, it
// will be recalculated, given the new scale factor.
cached_minimize_button_x_delta_ = 0;
}
// This function attempts to calculate the odd and varying difference
// between the results of DwmGetWindowAttribute with the
// DWMWA_CAPTION_BUTTON_BOUNDS flag and the information from the
// WM_GETTITLEBARINFOEX message. It will return an empirically determined
// offset until the window has been activated and the message returns
// valid rectangles.
int MinimizeButtonMetrics::GetButtonBoundsPositionOffset(
const RECT& button_bounds,
const RECT& window_bounds) const {
if (button_bounds_position_offset_ == kInvalidOffset) {
if (!was_activated_ || !IsWindowVisible(hwnd_)) {
return kButtonBoundsPositionOffset;
}
TITLEBARINFOEX info = {0};
info.cbSize = sizeof(info);
SendMessage(hwnd_, WM_GETTITLEBARINFOEX, 0,
reinterpret_cast<LPARAM>(&info));
if (info.rgrect[2].right == info.rgrect[2].left ||
(info.rgstate[2] & (STATE_SYSTEM_INVISIBLE | STATE_SYSTEM_OFFSCREEN |
STATE_SYSTEM_UNAVAILABLE))) {
return kButtonBoundsPositionOffset;
}
button_bounds_position_offset_ =
info.rgrect[2].left - (button_bounds.left + window_bounds.left);
}
return button_bounds_position_offset_;
}
int MinimizeButtonMetrics::GetMinimizeButtonOffsetForWindow() const {
bool dwm_button_pos = false;
POINT minimize_button_corner = {0};
RECT button_bounds = {0};
if (SUCCEEDED(DwmGetWindowAttribute(hwnd_, DWMWA_CAPTION_BUTTON_BOUNDS,
&button_bounds, sizeof(button_bounds)))) {
if (button_bounds.left != button_bounds.right) {
// This converts the button coordinate into screen coordinates
// thus, ensuring that the identity switcher is placed in the
// same location as before. An additional constant is added because
// there is a difference between the caption button bounds and
// the values obtained through WM_GETTITLEBARINFOEX. This difference
// varies between OS versions, and no metric describing this difference
// has been located.
RECT window_bounds = {0};
if (GetWindowRect(hwnd_, &window_bounds)) {
int offset =
GetButtonBoundsPositionOffset(button_bounds, window_bounds);
minimize_button_corner = {
button_bounds.left + window_bounds.left + offset, 0};
dwm_button_pos = true;
}
}
}
if (!dwm_button_pos) {
// Fallback to using the message for the titlebar info only if the above
// code fails. It can fail if DWM is disabled globally or only for the
// given HWND. The WM_GETTITLEBARINFOEX message can fail if we are not
// active/visible. By fail we get a location of 0; the return status
// code is always the same and similarly the state never seems to change
// (titlebar_info.rgstate).
TITLEBARINFOEX titlebar_info = {0};
titlebar_info.cbSize = sizeof(TITLEBARINFOEX);
SendMessage(hwnd_, WM_GETTITLEBARINFOEX, 0,
reinterpret_cast<LPARAM>(&titlebar_info));
// Under DWM WM_GETTITLEBARINFOEX won't return the right thing until after
// WM_NCACTIVATE (maybe it returns classic values?). In an attempt to
// return a consistant value we cache the last value across instances and
// use it until we get the activate.
if (titlebar_info.rgrect[2].left == titlebar_info.rgrect[2].right ||
(titlebar_info.rgstate[2] &
(STATE_SYSTEM_INVISIBLE | STATE_SYSTEM_OFFSCREEN |
STATE_SYSTEM_UNAVAILABLE)))
return 0;
minimize_button_corner = {titlebar_info.rgrect[2].left, 0};
}
// WM_GETTITLEBARINFOEX returns rects in screen coordinates in pixels.
// DWMNA_CAPTION_BUTTON_BOUNDS is in window (not client) coordinates,
// but it has been converted to screen coordinates above. We need to
// convert the minimize button corner offset to DIP before returning it.
MapWindowPoints(HWND_DESKTOP, hwnd_, &minimize_button_corner, 1);
gfx::Point pixel_point = {minimize_button_corner.x, 0};
gfx::Point dip_point = ScreenWin::ClientToDIPPoint(hwnd_, pixel_point);
return dip_point.x();
}
int MinimizeButtonMetrics::GetMinimizeButtonOffsetX() const {
// Under DWM WM_GETTITLEBARINFOEX won't return the right thing until after
// WM_NCACTIVATE (maybe it returns classic values?). In an attempt to return a
// consistant value we cache the last value across instances and use it until
// we get the activate.
if (was_activated_ || cached_minimize_button_x_delta_ == 0) {
const int minimize_button_offset = GetAndCacheMinimizeButtonOffsetX();
if (minimize_button_offset > 0) {
return minimize_button_offset;
}
}
// If we fail to get the minimize button offset via the WM_GETTITLEBARINFOEX
// message then calculate and return this via the
// cached_minimize_button_x_delta_ member value. Please see
// CacheMinimizeButtonDelta() for more details.
DCHECK(cached_minimize_button_x_delta_);
if (base::i18n::IsRTL())
return cached_minimize_button_x_delta_;
RECT client_rect = {0};
GetClientRect(hwnd_, &client_rect);
return client_rect.right - cached_minimize_button_x_delta_;
}
int MinimizeButtonMetrics::GetAndCacheMinimizeButtonOffsetX() const {
const int minimize_button_offset = GetMinimizeButtonOffsetForWindow();
if (minimize_button_offset <= 0)
return 0;
if (base::i18n::IsRTL()) {
cached_minimize_button_x_delta_ = minimize_button_offset;
} else {
RECT client_rect = {0};
GetClientRect(hwnd_, &client_rect);
cached_minimize_button_x_delta_ =
client_rect.right - minimize_button_offset;
}
last_cached_minimize_button_x_delta_ = cached_minimize_button_x_delta_;
return minimize_button_offset;
}
Codebase Browser
chromium