Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 143 insertions, 0 deletions

diff --git a/gfx/src/X11Util.h b/gfx/src/X11Util.h
new file mode 100644
index 0000000000..fc583fb6d4
--- /dev/null
+++ b/gfx/src/X11Util.h
@@ -0,0 +1,143 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_X11Util_h
+#define mozilla_X11Util_h
+
+// Utilities common to all X clients, regardless of UI toolkit.
+
+#if defined(MOZ_WIDGET_GTK)
+#  include <gdk/gdk.h>
+#  include <gdk/gdkx.h>
+#  include "X11UndefineNone.h"
+#else
+#  error Unknown toolkit
+#endif
+
+#include <string.h>          // for memset
+#include "mozilla/Scoped.h"  // for SCOPED_TEMPLATE
+
+namespace mozilla {
+
+/**
+ * Return the default X Display created and used by the UI toolkit.
+ */
+inline Display* DefaultXDisplay() {
+#if defined(MOZ_WIDGET_GTK)
+  GdkDisplay* gdkDisplay = gdk_display_get_default();
+  if (GDK_IS_X11_DISPLAY(gdkDisplay)) {
+    return GDK_DISPLAY_XDISPLAY(gdkDisplay);
+  }
+#endif
+  return nullptr;
+}
+
+/**
+ * Sets *aVisual to point to aDisplay's Visual struct corresponding to
+ * aVisualID, and *aDepth to its depth.  When aVisualID is None, these are set
+ * to nullptr and 0 respectively.  Both out-parameter pointers are assumed
+ * non-nullptr.
+ */
+void FindVisualAndDepth(Display* aDisplay, VisualID aVisualID, Visual** aVisual,
+                        int* aDepth);
+
+/**
+ * Ensure that all X requests have been processed.
+ *
+ * This is similar to XSync, but doesn't need a round trip if the previous
+ * request was synchronous or if events have been received since the last
+ * request.  Subsequent FinishX calls will be noops if there have been no
+ * intermediate requests.
+ */
+
+void FinishX(Display* aDisplay);
+
+/**
+ * Invoke XFree() on a pointer to memory allocated by Xlib (if the
+ * pointer is nonnull) when this class goes out of scope.
+ */
+template <typename T>
+struct ScopedXFreePtrTraits {
+  typedef T* type;
+  static T* empty() { return nullptr; }
+  static void release(T* ptr) {
+    if (ptr != nullptr) XFree(ptr);
+  }
+};
+SCOPED_TEMPLATE(ScopedXFree, ScopedXFreePtrTraits)
+
+/**
+ * On construction, set a graceful X error handler that doesn't crash the
+ * application and records X errors. On destruction, restore the X error handler
+ * to what it was before construction.
+ *
+ * The SyncAndGetError() method allows to know whether a X error occurred,
+ * optionally allows to get the full XErrorEvent, and resets the recorded X
+ * error state so that a single X error will be reported only once.
+ *
+ * Nesting is correctly handled: multiple nested ScopedXErrorHandler's don't
+ * interfere with each other's state. However, if SyncAndGetError is not called
+ * on the nested ScopedXErrorHandler, then any X errors caused by X calls made
+ * while the nested ScopedXErrorHandler was in place may then be caught by the
+ * other ScopedXErrorHandler. This is just a result of X being asynchronous and
+ * us not doing any implicit syncing: the only method in this class what causes
+ * syncing is SyncAndGetError().
+ *
+ * This class is not thread-safe at all. It is assumed that only one thread is
+ * using any ScopedXErrorHandler's. Given that it's not used on Mac, it should
+ * be easy to make it thread-safe by using thread-local storage with __thread.
+ */
+class ScopedXErrorHandler {
+ public:
+  // trivial wrapper around XErrorEvent, just adding ctor initializing by zero.
+  struct ErrorEvent {
+    XErrorEvent mError;
+
+    ErrorEvent() { memset(this, 0, sizeof(ErrorEvent)); }
+  };
+
+ private:
+  // this ScopedXErrorHandler's ErrorEvent object
+  ErrorEvent mXError;
+
+  // static pointer for use by the error handler
+  static ErrorEvent* sXErrorPtr;
+
+  // what to restore sXErrorPtr to on destruction
+  ErrorEvent* mOldXErrorPtr;
+
+  // what to restore the error handler to on destruction
+  int (*mOldErrorHandler)(Display*, XErrorEvent*);
+
+ public:
+  static int ErrorHandler(Display*, XErrorEvent* ev);
+
+  /**
+   * @param aAllowOffMainThread whether to warn if used off main thread
+   */
+  explicit ScopedXErrorHandler(bool aAllowOffMainThread = false);
+
+  ~ScopedXErrorHandler();
+
+  /** \returns true if a X error occurred since the last time this method was
+   * called on this ScopedXErrorHandler object, or since the creation of this
+   * ScopedXErrorHandler object if this method was never called on it.
+   *
+   * \param ev this optional parameter, if set, will be filled with the
+   * XErrorEvent object. If multiple errors occurred, the first one will be
+   * returned.
+   */
+  bool SyncAndGetError(Display* dpy, XErrorEvent* ev = nullptr);
+};
+
+class OffMainThreadScopedXErrorHandler : public ScopedXErrorHandler {
+ public:
+  OffMainThreadScopedXErrorHandler() : ScopedXErrorHandler(true) {}
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_X11Util_h