Make Chromium windows not hide auto-hide taskbars.

There are a few caveats here:

* On Aero glass, if the auto-hide taskbar is at the top of the screen, we get one row of nonclient pixels along the bottom of the screen (not too noticeable for light-colored pages, looks a bit odd with a dark page).  I can't find a way around this.

* Switching between fullscreen and normal mode can leave things a bit confused until you click another app and then reactivate Chromium.  This seems to happen with other applications too (e.g. Firefox fullscreen mode) so I'm not too worried.

* Chromium does not deal well with toggling the taskbar's auto-hide setting (or, I think, its position?) unless you restore and remaximize the window.  I tried to fix this via modified handling of WM_SETTINGCHANGE but only made things worse and so gave up.

BUG=20
Review URL: http://codereview.chromium.org/28338

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@10845 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 117 insertions, 53 deletions

diff --git a/chrome/browser/views/frame/browser_frame.cc b/chrome/browser/views/frame/browser_frame.cc
index c318f37..a264908c 100644
--- a/chrome/browser/views/frame/browser_frame.cc
+++ b/chrome/browser/views/frame/browser_frame.cc
@@ -116,22 +116,49 @@ LRESULT BrowserFrame::OnNCCalcSize(BOOL mode, LPARAM l_param) {
   // We don't adjust the client area unless we're a tabbed browser window and
   // are using the native frame.
   if (!non_client_view_->UseNativeFrame() ||
-      !browser_view_->IsBrowserTypeNormal() || !mode) {
+      !browser_view_->IsBrowserTypeNormal()) {
     return Window::OnNCCalcSize(mode, l_param);
   }
 
-  // In fullscreen mode, we make the whole window client area.
-  if (!browser_view_->IsFullscreen()) {
-    NCCALCSIZE_PARAMS* params = reinterpret_cast<NCCALCSIZE_PARAMS*>(l_param);
-    int border_thickness = GetSystemMetrics(SM_CXSIZEFRAME);
-    params->rgrc[0].left += (border_thickness - kClientEdgeThickness);
-    params->rgrc[0].right -= (border_thickness - kClientEdgeThickness);
-    params->rgrc[0].bottom -= (border_thickness - kClientEdgeThickness);
+  RECT* client_rect = mode ?
+      &reinterpret_cast<NCCALCSIZE_PARAMS*>(l_param)->rgrc[0] :
+      reinterpret_cast<RECT*>(l_param);
+  int border_thickness = 0;
+  if (browser_view_->IsMaximized()) {
+    // Make the maximized mode client rect fit the screen exactly, by
+    // subtracting the border Windows automatically adds for maximized mode.
+    border_thickness = GetSystemMetrics(SM_CXSIZEFRAME);
+    // Find all auto-hide taskbars along the screen edges and adjust in by the
+    // thickness of the auto-hide taskbar on each such edge, so the window isn't
+    // treated as a "fullscreen app", which would cause the taskbars to
+    // disappear.
+    HMONITOR monitor = MonitorFromWindow(GetHWND(), MONITOR_DEFAULTTONEAREST);
+    if (win_util::EdgeHasAutoHideTaskbar(ABE_LEFT, monitor))
+      client_rect->left += win_util::kAutoHideTaskbarThicknessPx;
+    if (win_util::EdgeHasAutoHideTaskbar(ABE_RIGHT, monitor))
+      client_rect->right -= win_util::kAutoHideTaskbarThicknessPx;
+    if (win_util::EdgeHasAutoHideTaskbar(ABE_BOTTOM, monitor)) {
+      client_rect->bottom -= win_util::kAutoHideTaskbarThicknessPx;
+    } else if (win_util::EdgeHasAutoHideTaskbar(ABE_TOP, monitor)) {
+      // Tricky bit.  Due to a bug in DwmDefWindowProc()'s handling of
+      // WM_NCHITTEST, having any nonclient area atop the window causes the
+      // caption buttons to draw onscreen but not respond to mouse hover/clicks.
+      // So for a taskbar at the screen top, we can't push the client_rect->top
+      // down; instead, we move the bottom up by one pixel, which is the
+      // smallest change we can make and still get a client area less than the
+      // screen size. This is visibly ugly, but there seems to be no better
+      // solution.
+      --client_rect->bottom;
+    }
+  } else if (!browser_view_->IsFullscreen()) {
+    // We draw our own client edge over part of the default frame would be.
+    border_thickness = GetSystemMetrics(SM_CXSIZEFRAME) - kClientEdgeThickness;
   }
+  client_rect->left += border_thickness;
+  client_rect->right -= border_thickness;
+  client_rect->bottom -= border_thickness;
 
   UpdateDWMFrame();
-
-  SetMsgHandled(TRUE);
   return 0;
 }
 
@@ -140,9 +167,8 @@ LRESULT BrowserFrame::OnNCHitTest(const CPoint& pt) {
   if (non_client_view_->UseNativeFrame()) {
     LRESULT result;
     if (DwmDefWindowProc(GetHWND(), WM_NCHITTEST, 0, MAKELPARAM(pt.x, pt.y),
-                         &result)) {
+                         &result))
       return result;
-    }
   }
   return Window::OnNCHitTest(pt);
 }
@@ -179,12 +205,16 @@ void BrowserFrame::UpdateDWMFrame() {
   // because the GDI-drawn text in the web content composited over it will
   // become semi-transparent over any glass area.
   MARGINS margins = { 0 };
-  if (!browser_view_->IsFullscreen()) {
+  if (browser_view_->CanCurrentlyResize()) {
     margins.cxLeftWidth = kClientEdgeThickness + 1;
     margins.cxRightWidth = kClientEdgeThickness + 1;
+    margins.cyBottomHeight = kClientEdgeThickness + 1;
+  }
+  // In maximized mode, we only have a titlebar strip of glass, no side/bottom
+  // borders.
+  if (!browser_view_->IsFullscreen()) {
     margins.cyTopHeight =
         GetBoundsForTabStrip(browser_view_->tabstrip()).bottom();
-    margins.cyBottomHeight = kClientEdgeThickness + 1;
   }
   DwmExtendFrameIntoClientArea(GetHWND(), &margins);
 }
diff --git a/chrome/browser/views/frame/browser_frame.h b/chrome/browser/views/frame/browser_frame.h
index c7efcab..13dace7 100644
--- a/chrome/browser/views/frame/browser_frame.h
+++ b/chrome/browser/views/frame/browser_frame.h
@@ -55,9 +55,9 @@ class BrowserFrame : public views::Window {
   // Overridden from views::WidgetWin:
   virtual bool AcceleratorPressed(views::Accelerator* accelerator);
   virtual bool GetAccelerator(int cmd_id, views::Accelerator* accelerator);
-  virtual void OnInitMenuPopup(HMENU menu, UINT position, BOOL is_system_menu);
   virtual void OnEnterSizeMove();
   virtual void OnEndSession(BOOL ending, UINT logoff);
+  virtual void OnInitMenuPopup(HMENU menu, UINT position, BOOL is_system_menu);
   virtual LRESULT OnMouseActivate(HWND window,
                                   UINT hittest_code,
                                   UINT message);
diff --git a/chrome/browser/views/frame/glass_browser_frame_view.cc b/chrome/browser/views/frame/glass_browser_frame_view.cc
index 54982d7..8ca20b0 100644
--- a/chrome/browser/views/frame/glass_browser_frame_view.cc
+++ b/chrome/browser/views/frame/glass_browser_frame_view.cc
@@ -178,10 +178,10 @@ gfx::Rect GlassBrowserFrameView::GetWindowBoundsForClientBounds(
 gfx::Point GlassBrowserFrameView::GetSystemMenuPoint() const {
   gfx::Point system_menu_point;
   if (browser_view_->IsBrowserTypeNormal()) {
-    // The maximized mode bit here is because in maximized mode the frame edge
-    // and the client edge are both offscreen, whereas in the opaque frame
-    // (where we don't do this trick) maximized windows have no client edge and
-    // only the frame edge is offscreen.
+    // The maximized mode bit here is because in maximized mode there is no
+    // client edge, but in restored mode there is one, and unlike in the opaque
+    // frame we don't have a convenient function to get its coordinate (since
+    // FrameBorderThickness() won't do what we want).
     system_menu_point.SetPoint(NonClientBorderThickness() -
         (frame_->IsMaximized() ? 0 : kClientEdgeThickness),
         NonClientTopBorderHeight() + browser_view_->GetTabStripHeight() -
@@ -224,7 +224,8 @@ void GlassBrowserFrameView::Paint(ChromeCanvas* canvas) {
   PaintDistributorLogo(canvas);
   PaintToolbarBackground(canvas);
   PaintOTRAvatar(canvas);
-  PaintClientEdge(canvas);
+  if (!frame_->IsMaximized())
+    PaintRestoredClientEdge(canvas);
 }
 
 void GlassBrowserFrameView::Layout() {
@@ -237,16 +238,22 @@ void GlassBrowserFrameView::Layout() {
 // GlassBrowserFrameView, private:
 
 int GlassBrowserFrameView::FrameBorderThickness() const {
-  return GetSystemMetrics(SM_CXSIZEFRAME);
+  return browser_view_->CanCurrentlyResize() ?
+      GetSystemMetrics(SM_CXSIZEFRAME) : 0;
 }
 
 int GlassBrowserFrameView::NonClientBorderThickness() const {
-  return kNonClientBorderThickness;
+  return browser_view_->CanCurrentlyResize() ? kNonClientBorderThickness : 0;
 }
 
 int GlassBrowserFrameView::NonClientTopBorderHeight() const {
-  return FrameBorderThickness() +
-      (frame_->IsMaximized() ? 0 : kNonClientRestoredExtraThickness);
+  if (browser_view_->IsFullscreen())
+    return 0;
+  // We'd like to use FrameBorderThickness() here, but the maximized Aero glass
+  // frame has a 0 frame border around most edges and a CXSIZEFRAME-thick border
+  // at the top (see AeroGlassFrame::OnGetMinMaxInfo()).
+  return GetSystemMetrics(SM_CXSIZEFRAME) +
+      (browser_view_->IsMaximized() ? 0 : kNonClientRestoredExtraThickness);
 }
 
 void GlassBrowserFrameView::PaintDistributorLogo(ChromeCanvas* canvas) {
@@ -294,7 +301,7 @@ void GlassBrowserFrameView::PaintOTRAvatar(ChromeCanvas* canvas) {
       otr_avatar_bounds_.width(), otr_avatar_bounds_.height(), false);
 }
 
-void GlassBrowserFrameView::PaintClientEdge(ChromeCanvas* canvas) {
+void GlassBrowserFrameView::PaintRestoredClientEdge(ChromeCanvas* canvas) {
   // The client edges start below the toolbar upper corner images regardless
   // of how tall the toolbar itself is.
   int client_area_top =
diff --git a/chrome/browser/views/frame/glass_browser_frame_view.h b/chrome/browser/views/frame/glass_browser_frame_view.h
index f325dde..edaed89 100644
--- a/chrome/browser/views/frame/glass_browser_frame_view.h
+++ b/chrome/browser/views/frame/glass_browser_frame_view.h
@@ -54,7 +54,7 @@ class GlassBrowserFrameView : public BrowserNonClientFrameView {
   void PaintDistributorLogo(ChromeCanvas* canvas);
   void PaintToolbarBackground(ChromeCanvas* canvas);
   void PaintOTRAvatar(ChromeCanvas* canvas);
-  void PaintClientEdge(ChromeCanvas* canvas);
+  void PaintRestoredClientEdge(ChromeCanvas* canvas);
 
   // Layout various sub-components of this view.
   void LayoutDistributorLogo();
diff --git a/chrome/browser/views/frame/opaque_browser_frame_view.cc b/chrome/browser/views/frame/opaque_browser_frame_view.cc
index 98a71c3..a908d7f 100644
--- a/chrome/browser/views/frame/opaque_browser_frame_view.cc
+++ b/chrome/browser/views/frame/opaque_browser_frame_view.cc
@@ -505,7 +505,7 @@ void OpaqueBrowserFrameView::GetWindowMask(const gfx::Size& size,
                                            gfx::Path* window_mask) {
   DCHECK(window_mask);
 
-  if (browser_view_->IsFullscreen())
+  if (!browser_view_->CanCurrentlyResize())
     return;
 
   // Redefine the window visible region for the new size.
@@ -647,10 +647,7 @@ SkBitmap OpaqueBrowserFrameView::GetFavIconForTabIconView() {
 // OpaqueBrowserFrameView, private:
 
 int OpaqueBrowserFrameView::FrameBorderThickness() const {
-  if (browser_view_->IsFullscreen())
-    return 0;
-  return frame_->IsMaximized() ?
-      GetSystemMetrics(SM_CXSIZEFRAME) : kFrameBorderThickness;
+  return browser_view_->CanCurrentlyResize() ? kFrameBorderThickness : 0;
 }
 
 int OpaqueBrowserFrameView::TopResizeHeight() const {
@@ -918,13 +915,11 @@ void OpaqueBrowserFrameView::LayoutWindowControls() {
   // button to the screen corner to obey Fitts' Law.
   int right_extra_width = is_maximized ?
       (kFrameBorderThickness - kFrameShadowThickness) : 0;
-  int right_spacing = is_maximized ?
-      (GetSystemMetrics(SM_CXSIZEFRAME) + right_extra_width) : frame_thickness;
   gfx::Size close_button_size = close_button_->GetPreferredSize();
-  close_button_->SetBounds(width() - close_button_size.width() - right_spacing,
-                           caption_y,
-                           close_button_size.width() + right_extra_width,
-                           close_button_size.height() + top_extra_height);
+  close_button_->SetBounds(width() - close_button_size.width() -
+      right_extra_width - frame_thickness, caption_y,
+      close_button_size.width() + right_extra_width,
+      close_button_size.height() + top_extra_height);
 
   // When the window is restored, we show a maximized button; otherwise, we show
   // a restore button.
diff --git a/chrome/common/win_util.cc b/chrome/common/win_util.cc
index 7437031..50850d1 100644
--- a/chrome/common/win_util.cc
+++ b/chrome/common/win_util.cc
@@ -28,6 +28,8 @@
 
 namespace win_util {
 
+const int kAutoHideTaskbarThicknessPx = 2;
+
 namespace {
 
 // Enforce visible dialog box.
@@ -624,6 +626,16 @@ void CenterAndSizeWindow(HWND parent, HWND window, const SIZE& pref,
   }
 }
 
+bool EdgeHasAutoHideTaskbar(UINT edge, HMONITOR monitor) {
+  APPBARDATA taskbar_data = { 0 };
+  taskbar_data.cbSize = sizeof APPBARDATA;
+  taskbar_data.uEdge = edge;
+  HWND taskbar = reinterpret_cast<HWND>(SHAppBarMessage(ABM_GETAUTOHIDEBAR,
+                                                        &taskbar_data));
+  return ::IsWindow(taskbar) &&
+      (MonitorFromWindow(taskbar, MONITOR_DEFAULTTONEAREST) == monitor);
+}
+
 HANDLE GetSectionFromProcess(HANDLE section, HANDLE process, bool read_only) {
   HANDLE valid_section = NULL;
   DWORD access = STANDARD_RIGHTS_REQUIRED | FILE_MAP_READ;
diff --git a/chrome/common/win_util.h b/chrome/common/win_util.h
index c93b098..8e703cb 100644
--- a/chrome/common/win_util.h
+++ b/chrome/common/win_util.h
@@ -211,6 +211,10 @@ void AdjustWindowToFit(HWND hwnd);
 void CenterAndSizeWindow(HWND parent, HWND window, const SIZE& pref,
                          bool pref_is_client);
 
+// Returns true if edge |edge| (one of ABE_LEFT, TOP, RIGHT, or BOTTOM) of
+// monitor |monitor| has an auto-hiding taskbar.
+bool EdgeHasAutoHideTaskbar(UINT edge, HMONITOR monitor);
+
 // Duplicates a section handle from another process to the current process.
 // Returns the new valid handle if the function succeed. NULL otherwise.
 HANDLE GetSectionFromProcess(HANDLE section, HANDLE process, bool read_only);
@@ -274,6 +278,9 @@ int MessageBox(HWND hwnd,
 // Returns the system set window title font.
 ChromeFont GetWindowTitleFont();
 
+// The thickness of an auto-hide taskbar in pixels.
+extern const int kAutoHideTaskbarThicknessPx;
+
 }  // namespace win_util
 
 #endif  // CHROME_COMMON_WIN_UTIL_H_
diff --git a/chrome/views/window.cc b/chrome/views/window.cc
index d0875d8..80c6f31 100644
--- a/chrome/views/window.cc
+++ b/chrome/views/window.cc
@@ -561,8 +561,32 @@ LRESULT Window::OnNCCalcSize(BOOL mode, LPARAM l_param) {
   if (non_client_view_->UseNativeFrame())
     return WidgetWin::OnNCCalcSize(mode, l_param);
 
+  RECT* client_rect = mode ?
+      &reinterpret_cast<NCCALCSIZE_PARAMS*>(l_param)->rgrc[0] :
+      reinterpret_cast<RECT*>(l_param);
+  if (IsMaximized()) {
+    // Make the maximized mode client rect fit the screen exactly, by
+    // subtracting the border Windows automatically adds for maximized mode.
+    int border_thickness = GetSystemMetrics(SM_CXSIZEFRAME);
+    InflateRect(client_rect, -border_thickness, -border_thickness);
+
+    // Find all auto-hide taskbars along the screen edges and adjust in by the
+    // thickness of the auto-hide taskbar on each such edge, so the window isn't
+    // treated as a "fullscreen app", which would cause the taskbars to
+    // disappear.
+    HMONITOR monitor = MonitorFromWindow(GetHWND(), MONITOR_DEFAULTTONEAREST);
+    if (win_util::EdgeHasAutoHideTaskbar(ABE_LEFT, monitor))
+      client_rect->left += win_util::kAutoHideTaskbarThicknessPx;
+    if (win_util::EdgeHasAutoHideTaskbar(ABE_TOP, monitor))
+      client_rect->top += win_util::kAutoHideTaskbarThicknessPx;
+    if (win_util::EdgeHasAutoHideTaskbar(ABE_RIGHT, monitor))
+      client_rect->right -= win_util::kAutoHideTaskbarThicknessPx;
+    if (win_util::EdgeHasAutoHideTaskbar(ABE_BOTTOM, monitor))
+      client_rect->bottom -= win_util::kAutoHideTaskbarThicknessPx;
+  }
+
   // We need to repaint all when the window bounds change.
-  return WVR_REDRAW;
+  return mode ? WVR_REDRAW : 0;
 }
 
 LRESULT Window::OnNCHitTest(const CPoint& point) {
@@ -1077,21 +1101,10 @@ void Window::ResetWindowRegion(bool force) {
   CRect window_rect;
   GetWindowRect(&window_rect);
   HRGN new_region;
-  if (IsMaximized()) {
-    HMONITOR monitor = MonitorFromWindow(GetHWND(), MONITOR_DEFAULTTONEAREST);
-    MONITORINFO mi;
-    mi.cbSize = sizeof mi;
-    GetMonitorInfo(monitor, &mi);
-    CRect work_rect = mi.rcWork;
-    work_rect.OffsetRect(-window_rect.left, -window_rect.top);
-    new_region = CreateRectRgnIndirect(&work_rect);
-  } else {
-    gfx::Path window_mask;
-    non_client_view_->GetWindowMask(gfx::Size(window_rect.Width(),
-                                              window_rect.Height()),
-                                    &window_mask);
-    new_region = window_mask.CreateHRGN();
-  }
+  gfx::Path window_mask;
+  non_client_view_->GetWindowMask(
+      gfx::Size(window_rect.Width(), window_rect.Height()), &window_mask);
+  new_region = window_mask.CreateHRGN();
 
   if (current_rgn_result == ERROR || !EqualRgn(current_rgn, new_region)) {
     // SetWindowRgn takes ownership of the HRGN created by CreateHRGN.