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, or 0x0 if resize is not supported.

[Wez, 2012/09/25 20:48:29]

nit: Is the implementation _required_ to return 0x0 if resize is not supported,
or can it / should it return the actual desktop size?

[Jamie, 2012/09/25 23:20:20]

It doesn't actually matter. If it returns non-zero, then it will get asked to
reset to that size when the connection closes, which it will presumably ignore.
I'll change the comment to require it.

+  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, since monitor configurations

[Wez, 2012/09/25 20:48:29]

nit: Move the "since ... fly" part to the end of the sentence.

[Jamie, 2012/09/25 23:20:20]

Done.

+  // may change on the fly, implementations should fail gracefully if the
+  // specified size is no longer supported.
+  virtual void SetSize(const SkISize& size) = 0;
+
+  // Restore the original desktop size. This is separate from |SetSize|

[Wez, 2012/09/25 20:48:29]

nit: Clarify what |original| is for, e.g: "Restore the original desktop size.
The caller must provide the current size reported by the DesktopResizer in
|original|, as a hint. Implementations are free to ignore this, for example
virtual hosts typically ignore the call to avoid unnecessary resize operations."

[Jamie, 2012/09/25 23:20:20]

Done.

+  // because some implementations may handle it differently. For example, a
+  // virtual host could ignore this call to avoid an unnecessary resize and
+  // the resulting window layout changes that might ensue.
+  virtual void RestoreSize(const SkISize& original) = 0;
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_DESKTOP_RESIZER_H_