Transform Control Pattern
Describes guidelines and conventions for implementing ITransformProvider and ITransformProvider2, including information about properties and methods. The Transform control pattern is used to support controls that can be moved, resized, or rotated within a two-dimensional space.
For examples of controls that implement this control pattern, see Control Types and Their Supported Control Patterns.
This topic contains the following sections.
Implementation Guidelines and Conventions
When implementing the Transform control pattern, note the following guidelines and conventions:
- Support for this control pattern is not limited to objects on the desktop. This control pattern must also be supported by the children of a container object if the children can be moved, resized, or rotated freely within the boundaries of the container.
- An object cannot be moved, resized, or rotated such that its resulting screen location would be completely outside the coordinates of its container and therefore inaccessible to the keyboard or mouse (for example, when a top-level window is moved off-screen or a child object is moved outside the boundaries of the container's viewport). In these cases, the object is placed as close to the requested screen coordinates as possible with the top or left coordinates overridden to be within the container boundaries.
- For multi-monitor systems, if an object is moved, resized, or rotated completely outside the combined desktop screen coordinates, the object is placed on the primary monitor as close to the requested coordinates as possible.
- All parameters and property values are absolute and independent of locale.
Required Members for ITransformProvider
The following properties and methods are required for implementing the ITransformProvider interface.
| Required members | Member type | Notes |
|---|---|---|
| CanMove | Property | None |
| CanResize | Property | None |
| CanRotate | Property | None |
| Move | Method | None |
| Resize | Method | None |
| Rotate | Method | None |
The following additional properties and methods are required for implementing the ITransformProvider2 interface.
| Required members | Member type | Notes |
|---|---|---|
| CanZoom | Property | None |
| Zoom | Method | None |
| ZoomByUnit | Method | None |
| ZoomLevel | Property | None |
| ZoomMaximum | Property | None |
| ZoomMinimum | Property | None |
This control pattern has no associated events.
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