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/* 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 */
#ifndef mozilla_DimensionRequest_h
#define mozilla_DimensionRequest_h
#include "Units.h"
#include "mozilla/Maybe.h"
class nsIBaseWindow;
class nsIDocShellTreeOwner;
namespace mozilla {
enum class DimensionKind { Inner, Outer };
* DimensionRequest allows to request the change of some dimensions without
* having to specify the unchanged dimensions. This is specifically necessary
* when a change is initiated from a child process, which might not have an
* up-to-date view of its latest dimensions. Having to specify the missing
* dimensions with an outdated view can revert a previous change.
* The following series of changes `window.screenX = 10; window.screenY = 10;`
* essentially translates into two moveTo() calls. For the second call we want
* to account for changes made by the first call. From a child process we would
* end up crafting the second call without knowing the results of the first
* call. In the parent process we have access to results of the first call
* before crafting the second one. Although on Linux even the parent process
* doesn't have immediate access to the results of the last change.
* Note: The concept of an inner position is not present on
* nsIDocShellTreeOwner and nsIBaseWindow. A request specifying an inner
* position will return an NS_ERROR_NOT_IMPLEMENTED.
struct DimensionRequest {
DimensionKind mDimensionKind;
Maybe<LayoutDeviceIntCoord> mX;
Maybe<LayoutDeviceIntCoord> mY;
Maybe<LayoutDeviceIntCoord> mWidth;
Maybe<LayoutDeviceIntCoord> mHeight;
* Fills the missing dimensions with values obtained from `aSource`. Whether
* inner dimensions are supported depends on the implementation of
* `nsIBaseWindow::GetDimensions` for `aSource`.
* @param aSource The source for the missing dimensions.
nsresult SupplementFrom(nsIBaseWindow* aSource);
* Changes the outer size and or position of `aTarget`. Only outer dimensions
* are supported.
* @param aTarget The target whose size or position we want to change.
nsresult ApplyOuterTo(nsIBaseWindow* aTarget);
* Changes the inner size of `aTarget`. Only inner dimensions are supported.
* @param aTarget The target whose size we want to change.
nsresult ApplyInnerTo(nsIDocShellTreeOwner* aTarget, bool aAsRootShell);
} // namespace mozilla
#endif // mozilla_DimensionRequest_h