/* * Copyright 2010 The WebRTC Project Authors. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include "webrtc/base/x11windowpicker.h" #include #include #include #include #include #include #include #include #include "webrtc/base/logging.h" namespace rtc { // Convenience wrapper for XGetWindowProperty results. template class XWindowProperty { public: XWindowProperty(Display* display, Window window, Atom property) : data_(NULL) { const int kBitsPerByte = 8; Atom actual_type; int actual_format; unsigned long bytes_after; // NOLINT: type required by XGetWindowProperty int status = XGetWindowProperty(display, window, property, 0L, ~0L, False, AnyPropertyType, &actual_type, &actual_format, &size_, &bytes_after, &data_); succeeded_ = (status == Success); if (!succeeded_) { data_ = NULL; // Ensure nothing is freed. } else if (sizeof(PropertyType) * kBitsPerByte != actual_format) { LOG(LS_WARNING) << "Returned type size differs from " "requested type size."; succeeded_ = false; // We still need to call XFree in this case, so leave data_ alone. } if (!succeeded_) { size_ = 0; } } ~XWindowProperty() { if (data_) { XFree(data_); } } bool succeeded() const { return succeeded_; } size_t size() const { return size_; } const PropertyType* data() const { return reinterpret_cast(data_); } PropertyType* data() { return reinterpret_cast(data_); } private: bool succeeded_; unsigned long size_; // NOLINT: type required by XGetWindowProperty unsigned char* data_; RTC_DISALLOW_COPY_AND_ASSIGN(XWindowProperty); }; // Stupid X11. It seems none of the synchronous returns codes from X11 calls // are meaningful unless an asynchronous error handler is configured. This // RAII class registers and unregisters an X11 error handler. class XErrorSuppressor { public: explicit XErrorSuppressor(Display* display) : display_(display), original_error_handler_(NULL) { SuppressX11Errors(); } ~XErrorSuppressor() { UnsuppressX11Errors(); } private: static int ErrorHandler(Display* display, XErrorEvent* e) { char buf[256]; XGetErrorText(display, e->error_code, buf, sizeof buf); LOG(LS_WARNING) << "Received X11 error \"" << buf << "\" for request code " << static_cast(e->request_code); return 0; } void SuppressX11Errors() { XFlush(display_); XSync(display_, False); original_error_handler_ = XSetErrorHandler(&ErrorHandler); } void UnsuppressX11Errors() { XFlush(display_); XSync(display_, False); XErrorHandler handler = XSetErrorHandler(original_error_handler_); if (handler != &ErrorHandler) { LOG(LS_WARNING) << "Unbalanced XSetErrorHandler() calls detected. " << "Final error handler may not be what you expect!"; } original_error_handler_ = NULL; } Display* display_; XErrorHandler original_error_handler_; RTC_DISALLOW_COPY_AND_ASSIGN(XErrorSuppressor); }; // Hiding all X11 specifics inside its own class. This to avoid // conflicts between talk and X11 header declarations. class XWindowEnumerator { public: XWindowEnumerator() : display_(NULL), has_composite_extension_(false), has_render_extension_(false) { } ~XWindowEnumerator() { if (display_ != NULL) { XCloseDisplay(display_); } } bool Init() { if (display_ != NULL) { // Already initialized. return true; } display_ = XOpenDisplay(NULL); if (display_ == NULL) { LOG(LS_ERROR) << "Failed to open display."; return false; } XErrorSuppressor error_suppressor(display_); wm_state_ = XInternAtom(display_, "WM_STATE", True); net_wm_icon_ = XInternAtom(display_, "_NET_WM_ICON", False); int event_base, error_base, major_version, minor_version; if (XCompositeQueryExtension(display_, &event_base, &error_base) && XCompositeQueryVersion(display_, &major_version, &minor_version) && // XCompositeNameWindowPixmap() requires version 0.2 (major_version > 0 || minor_version >= 2)) { has_composite_extension_ = true; } else { LOG(LS_INFO) << "Xcomposite extension not available or too old."; } if (XRenderQueryExtension(display_, &event_base, &error_base) && XRenderQueryVersion(display_, &major_version, &minor_version) && // XRenderSetPictureTransform() requires version 0.6 (major_version > 0 || minor_version >= 6)) { has_render_extension_ = true; } else { LOG(LS_INFO) << "Xrender extension not available or too old."; } return true; } bool EnumerateWindows(WindowDescriptionList* descriptions) { if (!Init()) { return false; } XErrorSuppressor error_suppressor(display_); int num_screens = XScreenCount(display_); bool result = false; for (int i = 0; i < num_screens; ++i) { if (EnumerateScreenWindows(descriptions, i)) { // We know we succeded on at least one screen. result = true; } } return result; } bool EnumerateDesktops(DesktopDescriptionList* descriptions) { if (!Init()) { return false; } XErrorSuppressor error_suppressor(display_); Window default_root_window = XDefaultRootWindow(display_); int num_screens = XScreenCount(display_); for (int i = 0; i < num_screens; ++i) { Window root_window = XRootWindow(display_, i); DesktopId id(DesktopId(root_window, i)); // TODO: Figure out an appropriate desktop title. DesktopDescription desc(id, ""); desc.set_primary(root_window == default_root_window); descriptions->push_back(desc); } return num_screens > 0; } bool IsVisible(const WindowId& id) { if (!Init()) { return false; } XErrorSuppressor error_suppressor(display_); XWindowAttributes attr; if (!XGetWindowAttributes(display_, id.id(), &attr)) { LOG(LS_ERROR) << "XGetWindowAttributes() failed"; return false; } return attr.map_state == IsViewable; } bool MoveToFront(const WindowId& id) { if (!Init()) { return false; } XErrorSuppressor error_suppressor(display_); unsigned int num_children; Window* children; Window parent; Window root; // Find root window to pass event to. int status = XQueryTree(display_, id.id(), &root, &parent, &children, &num_children); if (status == 0) { LOG(LS_WARNING) << "Failed to query for child windows."; return false; } if (children != NULL) { XFree(children); } // Move the window to front. XRaiseWindow(display_, id.id()); // Some window managers (e.g., metacity in GNOME) consider it illegal to // raise a window without also giving it input focus with // _NET_ACTIVE_WINDOW, so XRaiseWindow() on its own isn't enough. Atom atom = XInternAtom(display_, "_NET_ACTIVE_WINDOW", True); if (atom != None) { XEvent xev; long event_mask; xev.xclient.type = ClientMessage; xev.xclient.serial = 0; xev.xclient.send_event = True; xev.xclient.window = id.id(); xev.xclient.message_type = atom; // The format member is set to 8, 16, or 32 and specifies whether the // data should be viewed as a list of bytes, shorts, or longs. xev.xclient.format = 32; xev.xclient.data.l[0] = 0; xev.xclient.data.l[1] = 0; xev.xclient.data.l[2] = 0; xev.xclient.data.l[3] = 0; xev.xclient.data.l[4] = 0; event_mask = SubstructureRedirectMask | SubstructureNotifyMask; XSendEvent(display_, root, False, event_mask, &xev); } XFlush(display_); return true; } uint8_t* GetWindowIcon(const WindowId& id, int* width, int* height) { if (!Init()) { return NULL; } XErrorSuppressor error_suppressor(display_); Atom ret_type; int format; unsigned long length, bytes_after, size; unsigned char* data = NULL; // Find out the size of the icon data. if (XGetWindowProperty( display_, id.id(), net_wm_icon_, 0, 0, False, XA_CARDINAL, &ret_type, &format, &length, &size, &data) == Success && data) { XFree(data); } else { LOG(LS_ERROR) << "Failed to get size of the icon."; return NULL; } // Get the icon data, the format is one uint32_t each for width and height, // followed by the actual pixel data. if (size >= 2 && XGetWindowProperty( display_, id.id(), net_wm_icon_, 0, size, False, XA_CARDINAL, &ret_type, &format, &length, &bytes_after, &data) == Success && data) { uint32_t* data_ptr = reinterpret_cast(data); int w, h; w = data_ptr[0]; h = data_ptr[1]; if (size < static_cast(w * h + 2)) { XFree(data); LOG(LS_ERROR) << "Not a vaild icon."; return NULL; } uint8_t* rgba = ArgbToRgba(&data_ptr[2], 0, 0, w, h, w, h, true); XFree(data); *width = w; *height = h; return rgba; } else { LOG(LS_ERROR) << "Failed to get window icon data."; return NULL; } } uint8_t* GetWindowThumbnail(const WindowId& id, int width, int height) { if (!Init()) { return NULL; } if (!has_composite_extension_) { // Without the Xcomposite extension we would only get a good thumbnail if // the whole window is visible on screen and not covered by any // other window. This is not something we want so instead, just // bail out. LOG(LS_INFO) << "No Xcomposite extension detected."; return NULL; } XErrorSuppressor error_suppressor(display_); Window root; int x; int y; unsigned int src_width; unsigned int src_height; unsigned int border_width; unsigned int depth; // In addition to needing X11 server-side support for Xcomposite, it // actually needs to be turned on for this window in order to get a good // thumbnail. If the user has modern hardware/drivers but isn't using a // compositing window manager, that won't be the case. Here we // automatically turn it on for shareable windows so that we can get // thumbnails. We used to avoid it because the transition is visually ugly, // but recent window managers don't always redirect windows which led to // no thumbnails at all, which is a worse experience. // Redirect drawing to an offscreen buffer (ie, turn on compositing). // X11 remembers what has requested this and will turn it off for us when // we exit. XCompositeRedirectWindow(display_, id.id(), CompositeRedirectAutomatic); Pixmap src_pixmap = XCompositeNameWindowPixmap(display_, id.id()); if (!src_pixmap) { // Even if the backing pixmap doesn't exist, this still should have // succeeded and returned a valid handle (it just wouldn't be a handle to // anything). So this is a real error path. LOG(LS_ERROR) << "XCompositeNameWindowPixmap() failed"; return NULL; } if (!XGetGeometry(display_, src_pixmap, &root, &x, &y, &src_width, &src_height, &border_width, &depth)) { // If the window does not actually have a backing pixmap, this is the path // that will "fail", so it's a warning rather than an error. LOG(LS_WARNING) << "XGetGeometry() failed (probably composite is not in " << "use)"; XFreePixmap(display_, src_pixmap); return NULL; } // If we get to here, then composite is in use for this window and it has a // valid backing pixmap. XWindowAttributes attr; if (!XGetWindowAttributes(display_, id.id(), &attr)) { LOG(LS_ERROR) << "XGetWindowAttributes() failed"; XFreePixmap(display_, src_pixmap); return NULL; } uint8_t* data = GetDrawableThumbnail(src_pixmap, attr.visual, src_width, src_height, width, height); XFreePixmap(display_, src_pixmap); return data; } int GetNumDesktops() { if (!Init()) { return -1; } return XScreenCount(display_); } uint8_t* GetDesktopThumbnail(const DesktopId& id, int width, int height) { if (!Init()) { return NULL; } XErrorSuppressor error_suppressor(display_); Window root_window = id.id(); XWindowAttributes attr; if (!XGetWindowAttributes(display_, root_window, &attr)) { LOG(LS_ERROR) << "XGetWindowAttributes() failed"; return NULL; } return GetDrawableThumbnail(root_window, attr.visual, attr.width, attr.height, width, height); } bool GetDesktopDimensions(const DesktopId& id, int* width, int* height) { if (!Init()) { return false; } XErrorSuppressor error_suppressor(display_); XWindowAttributes attr; if (!XGetWindowAttributes(display_, id.id(), &attr)) { LOG(LS_ERROR) << "XGetWindowAttributes() failed"; return false; } *width = attr.width; *height = attr.height; return true; } private: uint8_t* GetDrawableThumbnail(Drawable src_drawable, Visual* visual, int src_width, int src_height, int dst_width, int dst_height) { if (!has_render_extension_) { // Without the Xrender extension we would have to read the full window and // scale it down in our process. Xrender is over a decade old so we aren't // going to expend effort to support that situation. We still need to // check though because probably some virtual VNC displays are in this // category. LOG(LS_INFO) << "No Xrender extension detected."; return NULL; } XRenderPictFormat* format = XRenderFindVisualFormat(display_, visual); if (!format) { LOG(LS_ERROR) << "XRenderFindVisualFormat() failed"; return NULL; } // Create a picture to reference the window pixmap. XRenderPictureAttributes pa; pa.subwindow_mode = IncludeInferiors; // Don't clip child widgets Picture src = XRenderCreatePicture(display_, src_drawable, format, CPSubwindowMode, &pa); if (!src) { LOG(LS_ERROR) << "XRenderCreatePicture() failed"; return NULL; } // Create a picture to reference the destination pixmap. Pixmap dst_pixmap = XCreatePixmap(display_, src_drawable, dst_width, dst_height, format->depth); if (!dst_pixmap) { LOG(LS_ERROR) << "XCreatePixmap() failed"; XRenderFreePicture(display_, src); return NULL; } Picture dst = XRenderCreatePicture(display_, dst_pixmap, format, 0, NULL); if (!dst) { LOG(LS_ERROR) << "XRenderCreatePicture() failed"; XFreePixmap(display_, dst_pixmap); XRenderFreePicture(display_, src); return NULL; } // Clear the background. XRenderColor transparent = {0}; XRenderFillRectangle(display_, PictOpSrc, dst, &transparent, 0, 0, dst_width, dst_height); // Calculate how much we need to scale the image. double scale_x = static_cast(dst_width) / static_cast(src_width); double scale_y = static_cast(dst_height) / static_cast(src_height); double scale = std::min(scale_y, scale_x); int scaled_width = round(src_width * scale); int scaled_height = round(src_height * scale); // Render the thumbnail centered on both axis. int centered_x = (dst_width - scaled_width) / 2; int centered_y = (dst_height - scaled_height) / 2; // Scaling matrix XTransform xform = { { { XDoubleToFixed(1), XDoubleToFixed(0), XDoubleToFixed(0) }, { XDoubleToFixed(0), XDoubleToFixed(1), XDoubleToFixed(0) }, { XDoubleToFixed(0), XDoubleToFixed(0), XDoubleToFixed(scale) } } }; XRenderSetPictureTransform(display_, src, &xform); // Apply filter to smooth out the image. XRenderSetPictureFilter(display_, src, FilterBest, NULL, 0); // Render the image to the destination picture. XRenderComposite(display_, PictOpSrc, src, None, dst, 0, 0, 0, 0, centered_x, centered_y, scaled_width, scaled_height); // Get the pixel data from the X server. TODO: XGetImage // might be slow here, compare with ShmGetImage. XImage* image = XGetImage(display_, dst_pixmap, 0, 0, dst_width, dst_height, AllPlanes, ZPixmap); uint8_t* data = ArgbToRgba(reinterpret_cast(image->data), centered_x, centered_y, scaled_width, scaled_height, dst_width, dst_height, false); XDestroyImage(image); XRenderFreePicture(display_, dst); XFreePixmap(display_, dst_pixmap); XRenderFreePicture(display_, src); return data; } uint8_t* ArgbToRgba(uint32_t* argb_data, int x, int y, int w, int h, int stride_x, int stride_y, bool has_alpha) { uint8_t* p; int len = stride_x * stride_y * 4; uint8_t* data = new uint8_t[len]; memset(data, 0, len); p = data + 4 * (y * stride_x + x); for (int i = 0; i < h; ++i) { for (int j = 0; j < w; ++j) { uint32_t argb; uint32_t rgba; argb = argb_data[stride_x * (y + i) + x + j]; rgba = (argb << 8) | (argb >> 24); *p = rgba >> 24; ++p; *p = (rgba >> 16) & 0xff; ++p; *p = (rgba >> 8) & 0xff; ++p; *p = has_alpha ? rgba & 0xFF : 0xFF; ++p; } p += (stride_x - w) * 4; } return data; } bool EnumerateScreenWindows(WindowDescriptionList* descriptions, int screen) { Window parent; Window *children; int status; unsigned int num_children; Window root_window = XRootWindow(display_, screen); status = XQueryTree(display_, root_window, &root_window, &parent, &children, &num_children); if (status == 0) { LOG(LS_ERROR) << "Failed to query for child windows."; return false; } for (unsigned int i = 0; i < num_children; ++i) { // Iterate in reverse order to display windows from front to back. #ifdef CHROMEOS // TODO(jhorwich): Short-term fix for crbug.com/120229: Don't need to // filter, just return all windows and let the picker scan through them. Window app_window = children[num_children - 1 - i]; #else Window app_window = GetApplicationWindow(children[num_children - 1 - i]); #endif if (app_window && !X11WindowPicker::IsDesktopElement(display_, app_window)) { std::string title; if (GetWindowTitle(app_window, &title)) { WindowId id(app_window); WindowDescription desc(id, title); descriptions->push_back(desc); } } } if (children != NULL) { XFree(children); } return true; } bool GetWindowTitle(Window window, std::string* title) { int status; bool result = false; XTextProperty window_name; window_name.value = NULL; if (window) { status = XGetWMName(display_, window, &window_name); if (status && window_name.value && window_name.nitems) { int cnt; char **list = NULL; status = Xutf8TextPropertyToTextList(display_, &window_name, &list, &cnt); if (status >= Success && cnt && *list) { if (cnt > 1) { LOG(LS_INFO) << "Window has " << cnt << " text properties, only using the first one."; } *title = *list; result = true; } if (list != NULL) { XFreeStringList(list); } } if (window_name.value != NULL) { XFree(window_name.value); } } return result; } Window GetApplicationWindow(Window window) { Window root, parent; Window app_window = 0; Window *children; unsigned int num_children; Atom type = None; int format; unsigned long nitems, after; unsigned char *data; int ret = XGetWindowProperty(display_, window, wm_state_, 0L, 2, False, wm_state_, &type, &format, &nitems, &after, &data); if (ret != Success) { LOG(LS_ERROR) << "XGetWindowProperty failed with return code " << ret << " for window " << window << "."; return 0; } if (type != None) { int64_t state = static_cast(*data); XFree(data); return state == NormalState ? window : 0; } XFree(data); if (!XQueryTree(display_, window, &root, &parent, &children, &num_children)) { LOG(LS_ERROR) << "Failed to query for child windows although window" << "does not have a valid WM_STATE."; return 0; } for (unsigned int i = 0; i < num_children; ++i) { app_window = GetApplicationWindow(children[i]); if (app_window) { break; } } if (children != NULL) { XFree(children); } return app_window; } Atom wm_state_; Atom net_wm_icon_; Display* display_; bool has_composite_extension_; bool has_render_extension_; }; X11WindowPicker::X11WindowPicker() : enumerator_(new XWindowEnumerator()) { } X11WindowPicker::~X11WindowPicker() { } bool X11WindowPicker::IsDesktopElement(_XDisplay* display, Window window) { if (window == 0) { LOG(LS_WARNING) << "Zero is never a valid window."; return false; } // First look for _NET_WM_WINDOW_TYPE. The standard // (http://standards.freedesktop.org/wm-spec/latest/ar01s05.html#id2760306) // says this hint *should* be present on all windows, and we use the existence // of _NET_WM_WINDOW_TYPE_NORMAL in the property to indicate a window is not // a desktop element (that is, only "normal" windows should be shareable). Atom window_type_atom = XInternAtom(display, "_NET_WM_WINDOW_TYPE", True); XWindowProperty window_type(display, window, window_type_atom); if (window_type.succeeded() && window_type.size() > 0) { Atom normal_window_type_atom = XInternAtom( display, "_NET_WM_WINDOW_TYPE_NORMAL", True); uint32_t* end = window_type.data() + window_type.size(); bool is_normal = (end != std::find( window_type.data(), end, normal_window_type_atom)); return !is_normal; } // Fall back on using the hint. XClassHint class_hint; Status s = XGetClassHint(display, window, &class_hint); bool result = false; if (s == 0) { // No hints, assume this is a normal application window. return result; } static const std::string gnome_panel("gnome-panel"); static const std::string desktop_window("desktop_window"); if (gnome_panel.compare(class_hint.res_name) == 0 || desktop_window.compare(class_hint.res_name) == 0) { result = true; } XFree(class_hint.res_name); XFree(class_hint.res_class); return result; } bool X11WindowPicker::Init() { return enumerator_->Init(); } bool X11WindowPicker::GetWindowList(WindowDescriptionList* descriptions) { return enumerator_->EnumerateWindows(descriptions); } bool X11WindowPicker::GetDesktopList(DesktopDescriptionList* descriptions) { return enumerator_->EnumerateDesktops(descriptions); } bool X11WindowPicker::IsVisible(const WindowId& id) { return enumerator_->IsVisible(id); } bool X11WindowPicker::MoveToFront(const WindowId& id) { return enumerator_->MoveToFront(id); } uint8_t* X11WindowPicker::GetWindowIcon(const WindowId& id, int* width, int* height) { return enumerator_->GetWindowIcon(id, width, height); } uint8_t* X11WindowPicker::GetWindowThumbnail(const WindowId& id, int width, int height) { return enumerator_->GetWindowThumbnail(id, width, height); } int X11WindowPicker::GetNumDesktops() { return enumerator_->GetNumDesktops(); } uint8_t* X11WindowPicker::GetDesktopThumbnail(const DesktopId& id, int width, int height) { return enumerator_->GetDesktopThumbnail(id, width, height); } bool X11WindowPicker::GetDesktopDimensions(const DesktopId& id, int* width, int* height) { return enumerator_->GetDesktopDimensions(id, width, height); } } // namespace rtc