Manipulating 2D Views

This section describes the standard mechanisms provided by the Forms and Menus software for manipulating a 2D view using the mouse buttons, number keypad and function keys.

The mouse buttons are referred to as:

• MB2 (adjust)

• MB3 (popup)

  If you press MB3 when the cursor is over the view canvas, the popup view menu is displayed. This will either be the default menu supplied by the Forms and Menus software, or an application-specific version if provided, either by AVEVA or by your own customization.

  This section describes the default menu.

Zooming is done using:

• The MB2 (adjust) mouse button.

• The numeric keypad.

• PageUp, PageDown and Home keys

Panning is done using:

• The view scrollbars.

• The numeric keypad.

  Note the Reset Limits option on the View popup-menu, which will return to the initial view limits.

Zooming Using the Mouse Button MB2

To zoom in and out:

• Move the cursor to a corner of an imaginary box enclosing the area of interest. Hold down MB2, move the mouse to the diagonally opposite corner and release the button.

• Click MB2 to zoom out from the cursor position by factor of 1.5.

• Hold down Shift and click MB2 to zoom in on the cursor position by factor of 1.5.

• Hold down Ctrl as well to double the zoom factor.

Zooming Using Page Up, Page Down and Home Keys

These keys will be particularly useful on, for example, laptop keyboards, which frequently do not have a numeric keypad:

Panning Using the View Scrollbars

The view scroll bars enable you to pan across the view:

• The slider bubble pans continuously according to speed of movement.

• The arrowheads move the bubble by approximately 1/100 of the bar per click.

• Click in the slider trough to move the bubble by approximately 1/10 of the bar per click.

• Hold down Ctrl and click in the slider trough to pan to the opposite side in one step.

Manipulating 2D Views Using the Numeric Keypad

Panning Using Alt and the Arrow Keys

Each click pans the view by 1 step distance, where a step is half the size of the current displayed window.

• Holding down Ctrl does 10 steps.

• Holding down Shift does 0.1 step.

D View, Save and Restore View Methods

2D views now have 4 view stores that allow storage and retrieval of the current view state. They can be accessed by the saveview() and restoreview() methods:

!myview.SaveView( !storeNumber )

!myview.RestoreView( !storeNumber )

where !StoreNumber must be in the range 1 to 4.

If the view’s picture is deleted or changed then the view-stores are all cleared. The stored view settings should survive saving and restoring to a binary-save file.