root/ui/gfx/win/hwnd_util.cc

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DEFINITIONS

This source file includes following definitions.
  1. AdjustWindowToFit
  2. CrashOutOfMemory
  3. CrashAccessDenied
  4. CrashOther
  5. GetClassName
  6. SetWindowProc
  7. SetWindowUserData
  8. GetWindowUserData
  9. DoesWindowBelongToActiveWindow
  10. CenterAndSizeWindow
  11. CheckWindowCreated
  12. ShowSystemMenu
  13. ShowSystemMenuAtPoint
  14. GetWindowToParentTo

// Copyright (c) 2012 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/gfx/win/hwnd_util.h"

#include "base/i18n/rtl.h"
#include "base/strings/string_util.h"
#include "base/win/metro.h"
#include "base/win/win_util.h"
#include "ui/gfx/point.h"
#include "ui/gfx/rect.h"
#include "ui/gfx/size.h"

namespace gfx {

namespace {

// Adjust the window to fit.
void AdjustWindowToFit(HWND hwnd, const RECT& bounds, bool fit_to_monitor) {
  if (fit_to_monitor) {
    // Get the monitor.
    HMONITOR hmon = MonitorFromRect(&bounds, MONITOR_DEFAULTTONEAREST);
    if (hmon) {
      MONITORINFO mi;
      mi.cbSize = sizeof(mi);
      GetMonitorInfo(hmon, &mi);
      Rect window_rect(bounds);
      Rect monitor_rect(mi.rcWork);
      Rect new_window_rect = window_rect;
      new_window_rect.AdjustToFit(monitor_rect);
      if (new_window_rect != window_rect) {
        // Window doesn't fit on monitor, move and possibly resize.
        SetWindowPos(hwnd, 0, new_window_rect.x(), new_window_rect.y(),
                     new_window_rect.width(), new_window_rect.height(),
                     SWP_NOACTIVATE | SWP_NOZORDER);
        return;
      }
      // Else fall through.
    } else {
      NOTREACHED() << "Unable to find default monitor";
      // Fall through.
    }
  }  // Else fall through.

  // The window is not being fit to monitor, or the window fits on the monitor
  // as is, or we have no monitor info; reset the bounds.
  ::SetWindowPos(hwnd, 0, bounds.left, bounds.top,
                 bounds.right - bounds.left, bounds.bottom - bounds.top,
                 SWP_NOACTIVATE | SWP_NOZORDER);
}

// Turn off optimizations for these functions so they show up in crash reports.
MSVC_DISABLE_OPTIMIZE();

void CrashOutOfMemory() {
  LOG_GETLASTERROR(FATAL);
}

void CrashAccessDenied() {
  LOG_GETLASTERROR(FATAL);
}

// Crash isn't one of the ones we commonly see.
void CrashOther() {
  LOG_GETLASTERROR(FATAL);
}

MSVC_ENABLE_OPTIMIZE();

}  // namespace

base::string16 GetClassName(HWND window) {
  // GetClassNameW will return a truncated result (properly null terminated) if
  // the given buffer is not large enough.  So, it is not possible to determine
  // that we got the entire class name if the result is exactly equal to the
  // size of the buffer minus one.
  DWORD buffer_size = MAX_PATH;
  while (true) {
    std::wstring output;
    DWORD size_ret =
        GetClassNameW(window, WriteInto(&output, buffer_size), buffer_size);
    if (size_ret == 0)
      break;
    if (size_ret < (buffer_size - 1)) {
      output.resize(size_ret);
      return output;
    }
    buffer_size *= 2;
  }
  return std::wstring();  // error
}

#pragma warning(push)
#pragma warning(disable:4312 4244)

WNDPROC SetWindowProc(HWND hwnd, WNDPROC proc) {
  // The reason we don't return the SetwindowLongPtr() value is that it returns
  // the orignal window procedure and not the current one. I don't know if it is
  // a bug or an intended feature.
  WNDPROC oldwindow_proc =
      reinterpret_cast<WNDPROC>(GetWindowLongPtr(hwnd, GWLP_WNDPROC));
  SetWindowLongPtr(hwnd, GWLP_WNDPROC, reinterpret_cast<LONG_PTR>(proc));
  return oldwindow_proc;
}

void* SetWindowUserData(HWND hwnd, void* user_data) {
  return
      reinterpret_cast<void*>(SetWindowLongPtr(hwnd, GWLP_USERDATA,
          reinterpret_cast<LONG_PTR>(user_data)));
}

void* GetWindowUserData(HWND hwnd) {
  DWORD process_id = 0;
  DWORD thread_id = GetWindowThreadProcessId(hwnd, &process_id);
  // A window outside the current process needs to be ignored.
  if (process_id != ::GetCurrentProcessId())
    return NULL;
  return reinterpret_cast<void*>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
}

#pragma warning(pop)

bool DoesWindowBelongToActiveWindow(HWND window) {
  DCHECK(window);
  HWND top_window = ::GetAncestor(window, GA_ROOT);
  if (!top_window)
    return false;

  HWND active_top_window = ::GetAncestor(::GetForegroundWindow(), GA_ROOT);
  return (top_window == active_top_window);
}

void CenterAndSizeWindow(HWND parent,
                         HWND window,
                         const Size& pref) {
  DCHECK(window && pref.width() > 0 && pref.height() > 0);

  // Calculate the ideal bounds.
  RECT window_bounds;
  RECT center_bounds = {0};
  if (parent) {
    // If there is a parent, center over the parents bounds.
    ::GetWindowRect(parent, &center_bounds);
  }

  if (::IsRectEmpty(&center_bounds)) {
    // No parent or no parent rect. Center over the monitor the window is on.
    HMONITOR monitor = MonitorFromWindow(window, MONITOR_DEFAULTTONEAREST);
    if (monitor) {
      MONITORINFO mi = {0};
      mi.cbSize = sizeof(mi);
      GetMonitorInfo(monitor, &mi);
      center_bounds = mi.rcWork;
    } else {
      NOTREACHED() << "Unable to get default monitor";
    }
  }

  window_bounds.left = center_bounds.left;
  if (pref.width() < (center_bounds.right - center_bounds.left)) {
    window_bounds.left +=
        (center_bounds.right - center_bounds.left - pref.width()) / 2;
  }
  window_bounds.right = window_bounds.left + pref.width();

  window_bounds.top = center_bounds.top;
  if (pref.height() < (center_bounds.bottom - center_bounds.top)) {
    window_bounds.top +=
        (center_bounds.bottom - center_bounds.top - pref.height()) / 2;
  }
  window_bounds.bottom = window_bounds.top + pref.height();

  // If we're centering a child window, we are positioning in client
  // coordinates, and as such we need to offset the target rectangle by the
  // position of the parent window.
  if (::GetWindowLong(window, GWL_STYLE) & WS_CHILD) {
    DCHECK(parent && ::GetParent(window) == parent);
    POINT topleft = { window_bounds.left, window_bounds.top };
    ::MapWindowPoints(HWND_DESKTOP, parent, &topleft, 1);
    window_bounds.left = topleft.x;
    window_bounds.top = topleft.y;
    window_bounds.right = window_bounds.left + pref.width();
    window_bounds.bottom = window_bounds.top + pref.height();
  }

  AdjustWindowToFit(window, window_bounds, !parent);
}

void CheckWindowCreated(HWND hwnd) {
  if (!hwnd) {
    switch (GetLastError()) {
      case ERROR_NOT_ENOUGH_MEMORY:
        CrashOutOfMemory();
        break;
      case ERROR_ACCESS_DENIED:
        CrashAccessDenied();
        break;
      default:
        CrashOther();
        break;
    }
    LOG_GETLASTERROR(FATAL);
  }
}

void ShowSystemMenu(HWND window) {
  RECT rect;
  GetWindowRect(window, &rect);
  Point point = Point(base::i18n::IsRTL() ? rect.right : rect.left, rect.top);
  static const int kSystemMenuOffset = 10;
  point.Offset(base::i18n::IsRTL() ? -kSystemMenuOffset : kSystemMenuOffset,
               kSystemMenuOffset);
  ShowSystemMenuAtPoint(window, point);
}

void ShowSystemMenuAtPoint(HWND window, const Point& point) {
  // In the Metro process, we never want to show the system menu.
  if (base::win::IsMetroProcess())
    return;
  UINT flags = TPM_LEFTBUTTON | TPM_RIGHTBUTTON | TPM_RETURNCMD;
  if (base::i18n::IsRTL())
    flags |= TPM_RIGHTALIGN;
  HMENU menu = GetSystemMenu(window, FALSE);
  const int command =
      TrackPopupMenu(menu, flags, point.x(), point.y(), 0, window, NULL);
  if (command)
    SendMessage(window, WM_SYSCOMMAND, command, 0);
}

extern "C" {
  typedef HWND (*RootWindow)();
}

HWND GetWindowToParentTo(bool get_real_hwnd) {
  HMODULE metro = base::win::GetMetroModule();
  if (!metro)
    return get_real_hwnd ? ::GetDesktopWindow() : HWND_DESKTOP;
  // In windows 8 metro-mode the root window is not the desktop.
  RootWindow root_window =
      reinterpret_cast<RootWindow>(::GetProcAddress(metro, "GetRootWindow"));
  return root_window();
}

}  // namespace gfx

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