Cross-platform plumbing for resize-to-client

remoting/host/desktop_resizer.h

+// 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.
+
+#ifndef REMOTING_HOST_DESKTOP_RESIZER_H_
+#define REMOTING_HOST_DESKTOP_RESIZER_H_
+
+#include <list>
+
+#include "base/memory/scoped_ptr.h"
+#include "third_party/skia/include/core/SkRect.h"
+
+namespace remoting {
+
+class DesktopResizer {
+ public:
+  virtual ~DesktopResizer() {}
+
+  // Create a platform-specific DesktopResizer instance.
+  static scoped_ptr<DesktopResizer> Create();
+
+  // Return the current size of the desktop. If resize is not supported, the
+  // implementation should return 0x0, in which case none of the other API
+  // methods will be called.
+  virtual SkISize GetCurrentSize() = 0;
+
+  // Get the list of supported sizes, which should ideally include |preferred|.
+  // Implementations will generally do one of the following:
+  //   1. Return the list of sizes supported by the underlying video driver,
+  //      regardless of |preferred|.
+  //   2. Return a list containing just |preferred|, perhaps after imposing
+  //      some minimum size constraint. This will typically be the case if
+  //      there are no constraints imposed by the underlying video driver.
+  //   3. Return an empty list if resize is not supported.
+  virtual std::list<SkISize> GetSupportedSizes(const SkISize& preferred) = 0;
+
+  // Set the size of the desktop. |size| must be one of the sizes previously
+  // returned by |GetSupportedSizes|. Note that implementations should fail
+  // gracefully if the specified size is no longer supported, since monitor
+  // configurations may change on the fly.
+  virtual void SetSize(const SkISize& size) = 0;
+
+  // Restore the original desktop size. The caller must provide the original
+  // size of the desktop, as returned by |GetCurrentSize|, as a hint. However,
+  // implementaions are free to ignore this. For example, virtual hosts will
+  // typically ignore it to avoid unnecessary resize operations.
+  virtual void RestoreSize(const SkISize& original) = 0;
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_DESKTOP_RESIZER_H_