mirrors/electron
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages 1 Wiki Activity Actions 1

fix: allow chromium to handle WM_NCCALCSIZE for frameless windows (#21164)

Browse source
This commit is contained in:
Robo 2019-11-19 06:07:10 -08:00 • committed by GitHub
parent c8ed22def3
commit 73467f00e3
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
8 changed files with 205 additions and 206 deletions
Download patch file Download diff file Expand all files Collapse all files

195
shell/browser/native_window_views_win.cc
View file

@ -143,162 +143,28 @@ bool IsScreenReaderActive() {
return screenReader && UiaClientsAreListening();
}
// We use "enum" instead of "enum class" because we need to do bitwise compare.
enum AppbarAutohideEdge {
TOP = 1 << 0,
LEFT = 1 << 1,
BOTTOM = 1 << 2,
RIGHT = 1 << 3,
};
// The thickness of an auto-hide taskbar in pixel.
constexpr int kAutoHideTaskbarThicknessPx = 2;
// Code is copied from chrome_views_delegate_win.cc.
bool MonitorHasAutohideTaskbarForEdge(UINT edge, HMONITOR monitor) {
APPBARDATA taskbar_data = {sizeof(APPBARDATA), NULL, 0, edge};
taskbar_data.hWnd = ::GetForegroundWindow();
// MSDN documents an ABM_GETAUTOHIDEBAREX, which supposedly takes a monitor
// rect and returns autohide bars on that monitor. This sounds like a good
// idea for multi-monitor systems. Unfortunately, it appears to not work at
// least some of the time (erroneously returning NULL) and there's almost no
// online documentation or other sample code using it that suggests ways to
// address this problem. We do the following:-
// 1. Use the ABM_GETAUTOHIDEBAR message. If it works, i.e. returns a valid
// window we are done.
// 2. If the ABM_GETAUTOHIDEBAR message does not work we query the auto hide
// state of the taskbar and then retrieve its position. That call returns
// the edge on which the taskbar is present. If it matches the edge we
// are looking for, we are done.
// NOTE: This call spins a nested run loop.
HWND taskbar = reinterpret_cast<HWND>(
SHAppBarMessage(ABM_GETAUTOHIDEBAR, &taskbar_data));
if (!::IsWindow(taskbar)) {
APPBARDATA taskbar_data = {sizeof(APPBARDATA), 0, 0, 0};
unsigned int taskbar_state = SHAppBarMessage(ABM_GETSTATE, &taskbar_data);
if (!(taskbar_state & ABS_AUTOHIDE))
return false;
taskbar_data.hWnd = ::FindWindow(L"Shell_TrayWnd", NULL);
if (!::IsWindow(taskbar_data.hWnd))
return false;
SHAppBarMessage(ABM_GETTASKBARPOS, &taskbar_data);
if (taskbar_data.uEdge == edge)
taskbar = taskbar_data.hWnd;
}
// There is a potential race condition here:
// 1. A maximized chrome window is fullscreened.
// 2. It is switched back to maximized.
// 3. In the process the window gets a WM_NCCACLSIZE message which calls us to
// get the autohide state.
// 4. The worker thread is invoked. It calls the API to get the autohide
// state. On Windows versions earlier than Windows 7, taskbars could
// easily be always on top or not.
// This meant that we only want to look for taskbars which have the topmost
// bit set. However this causes problems in cases where the window on the
// main thread is still in the process of switching away from fullscreen.
// In this case the taskbar might not yet have the topmost bit set.
// 5. The main thread resumes and does not leave space for the taskbar and
// hence it does not pop when hovered.
//
// To address point 4 above, it is best to not check for the WS_EX_TOPMOST
// window style on the taskbar, as starting from Windows 7, the topmost
// style is always set. We don't support XP and Vista anymore.
if (::IsWindow(taskbar)) {
if (MonitorFromWindow(taskbar, MONITOR_DEFAULTTONEAREST) == monitor)
return true;
// In some cases like when the autohide taskbar is on the left of the
// secondary monitor, the MonitorFromWindow call above fails to return the
// correct monitor the taskbar is on. We fallback to MonitorFromPoint for
// the cursor position in that case, which seems to work well.
POINT cursor_pos = {0};
GetCursorPos(&cursor_pos);
if (MonitorFromPoint(cursor_pos, MONITOR_DEFAULTTONEAREST) == monitor)
return true;
}
return false;
}
int GetAppbarAutohideEdges(HWND hwnd) {
HMONITOR monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTONULL);
if (!monitor)
return 0;
int edges = 0;
if (MonitorHasAutohideTaskbarForEdge(ABE_LEFT, monitor))
edges |= AppbarAutohideEdge::LEFT;
if (MonitorHasAutohideTaskbarForEdge(ABE_TOP, monitor))
edges |= AppbarAutohideEdge::TOP;
if (MonitorHasAutohideTaskbarForEdge(ABE_RIGHT, monitor))
edges |= AppbarAutohideEdge::RIGHT;
if (MonitorHasAutohideTaskbarForEdge(ABE_BOTTOM, monitor))
edges |= AppbarAutohideEdge::BOTTOM;
return edges;
}
void TriggerNCCalcSize(HWND hwnd) {
RECT rcClient;
::GetWindowRect(hwnd, &rcClient);
::SetWindowPos(hwnd, NULL, rcClient.left, rcClient.top,
rcClient.right - rcClient.left, rcClient.bottom - rcClient.top,
SWP_FRAMECHANGED);
}
} // namespace
std::set<NativeWindowViews*> NativeWindowViews::forwarding_windows_;
HHOOK NativeWindowViews::mouse_hook_ = NULL;
void NativeWindowViews::Maximize() {
int autohide_edges = 0;
if (!has_frame())
autohide_edges = GetAppbarAutohideEdges(GetAcceleratedWidget());
// Only use Maximize() when:
// 1. window has WS_THICKFRAME style;
// 2. and window is not frameless when there is autohide taskbar.
if ((::GetWindowLong(GetAcceleratedWidget(), GWL_STYLE) & WS_THICKFRAME) &&
(has_frame() || autohide_edges == 0)) {
if (::GetWindowLong(GetAcceleratedWidget(), GWL_STYLE) & WS_THICKFRAME) {
if (IsVisible())
widget()->Maximize();
else
widget()->native_widget_private()->Show(ui::SHOW_STATE_MAXIMIZED,
gfx::Rect());
return;
} else {
restore_bounds_ = GetBounds();
auto display =
display::Screen::GetScreen()->GetDisplayNearestPoint(GetPosition());
SetBounds(display.work_area(), false);
}
gfx::Insets insets;
if (!has_frame()) {
// When taskbar is autohide, we need to leave some space so the window
// isn't treated as a "fullscreen app", which would cause the taskbars
// to disappear.
//
// This trick comes from hwnd_message_handler.cc. While Chromium already
// does this for normal window, somehow it is not applying the trick when
// using frameless window, and we have to do it ourselves.
float scale_factor =
display::win::ScreenWin::GetScaleFactorForHWND(GetAcceleratedWidget());
int thickness = std::ceil(kAutoHideTaskbarThicknessPx / scale_factor);
if (autohide_edges & AppbarAutohideEdge::LEFT)
insets.set_left(-thickness);
if (autohide_edges & AppbarAutohideEdge::TOP)
insets.set_top(-thickness);
if (autohide_edges & AppbarAutohideEdge::RIGHT)
insets.set_right(thickness);
if (autohide_edges & AppbarAutohideEdge::BOTTOM)
insets.set_bottom(thickness);
}
restore_bounds_ = GetBounds();
auto display =
display::Screen::GetScreen()->GetDisplayNearestPoint(GetPosition());
gfx::Rect bounds = display.work_area();
bounds.Inset(insets);
SetBounds(bounds, false);
}
bool NativeWindowViews::ExecuteWindowsCommand(int command_id) {
@ -363,45 +229,6 @@ bool NativeWindowViews::PreHandleMSG(UINT message,
return false;
}
case WM_NCCALCSIZE: {
if (!has_frame() && w_param == TRUE) {
NCCALCSIZE_PARAMS* params =
reinterpret_cast<NCCALCSIZE_PARAMS*>(l_param);
RECT PROPOSED = params->rgrc[0];
RECT BEFORE = params->rgrc[1];
// We need to call the default to have cascade and tile windows
// working
// (https://github.com/rossy/borderless-window/blob/master/borderless-window.c#L239),
// but we need to provide the proposed original value as suggested in
// https://blogs.msdn.microsoft.com/wpfsdk/2008/09/08/custom-window-chrome-in-wpf/
DefWindowProcW(GetAcceleratedWidget(), WM_NCCALCSIZE, w_param, l_param);
// When fullscreen the window has no border
int border = 0;
if (!IsFullscreen()) {
// When not fullscreen calculate the border size
border = GetSystemMetrics(SM_CXFRAME) +
GetSystemMetrics(SM_CXPADDEDBORDER);
if (!thick_frame_) {
border -= GetSystemMetrics(SM_CXBORDER);
}
}
if (last_window_state_ == ui::SHOW_STATE_MAXIMIZED) {
// Position the top of the frame offset from where windows thinks by
// exactly the border amount. When fullscreen this is 0.
params->rgrc[0].top = PROPOSED.top + border;
} else {
params->rgrc[0] = PROPOSED;
params->rgrc[1] = BEFORE;
}
return true;
} else {
return false;
}
}
case WM_COMMAND:
// Handle thumbar button click message.
if (HIWORD(w_param) == THBN_CLICKED)
@ -466,11 +293,6 @@ void NativeWindowViews::HandleSizeEvent(WPARAM w_param, LPARAM l_param) {
switch (w_param) {
case SIZE_MAXIMIZED: {
last_window_state_ = ui::SHOW_STATE_MAXIMIZED;
if (!has_frame()) {
TriggerNCCalcSize(GetAcceleratedWidget());
}
NotifyWindowMaximize();
break;
}
@ -491,11 +313,6 @@ void NativeWindowViews::HandleSizeEvent(WPARAM w_param, LPARAM l_param) {
case ui::SHOW_STATE_MAXIMIZED:
last_window_state_ = ui::SHOW_STATE_NORMAL;
NotifyWindowUnmaximize();
if (!has_frame()) {
TriggerNCCalcSize(GetAcceleratedWidget());
}
break;
case ui::SHOW_STATE_MINIMIZED:
if (IsFullscreen()) {