By AD Tejpal
This sample db demonstrates various methods for dragging / re-sizing / arranging of controls by user action on access form at run time. In each style, before closing the form, user has the option to save latest status of each control regarding its position and size. On next opening of form, controls will get depicted as per such saved status.
For a control to become eligible for drag and/or resize action, its tag property should include the words Drag and/or ReSize. At any stage, the user can undo the last action by clicking the UnDo command button. As and when desired, all such controls can be made to revert back to their original design settings by clicking the command button at bottom left. This command button also serves to toggle between design settings and last saved user settings.
Following alternative styles are demonstrated:
1 - Style A - It covers the following features:
1.1 - Drag / re-size by direct use of control's mouse events via class C_ControlsDDR. This class has an interesting feature: WithEvents functionality for different types of controls has been incorporated into a single class.
1.2 - Grouped controls manipulation. As the user drags the mouse (with left button in pressed state) around a set of controls, a red rectangle gets drawn accordingly and all controls falling within this rectangle are treated as a group. This group of controls can then be subjected to any of the following actions as desired:
(a) Drag the group of controls.
(b) Align the grouped controls Left / Right / Top / Bottom.
(c) ReSize the group as per Widest / Narrowest / Tallest / Shortest control.
(d) Make horizontal or vertical spacing amongst grouped controls equal.
1.3 - All controls enclosed by red rectangle drawn by the user (para 1.2 above) become subject to grouped action, even if not carrying the words Drag or ReSize in their tag values. For controls required to be kept immune to grouped action, the tag value should carry the word Exclude.
2 - Style B:
2.1 - It demonstrates induced manipulation of controls via drag/re-size handles - without depending upon mouse events of these controls. Three types of controls are illustrated, i.e. web browser, subform and image. Out of these, web browser and subform control do not have any mouse event of their own.
2.2 - As the user clicks upon the target control, drag handle appears at top left while resize handle appears at bottom right. Dragging on top left handle (with left button pressed) moves the control while similar action on resize handle leads to resizing.
3 - Style C:
3.1 - It demonstrates a completely non-intrusive approach towards induced manipulation of controls without depending upon any of their event. While three types of controls are illustrated, i.e. web browser, subform and image, this approach is universally applicable to all types of controls (including lines which do not have any event at all).
3.2 - As the user clicks anywhere on blank space of detail section near top left of target control, it is accompanied by automatic detection of that control. In confirmation, a red marker appears at top left of the control. Dragging the mouse (with left button pressed) on form detail section leads to induced movement of control identified by the marker.
3.3 - Similarly, when the user clicks anywhere on blank space of detail section near bottom right of target control, it is accompanied by automatic detection of that control. In confirmation, a red marker appears at bottom right of the control. Dragging the mouse (with left button pressed) on form detail section leads to induced resizing of control identified by the marker.
4 - Style D:
4.1 - It demonstrates a completely non-intrusive approach towards induced manipulation of lines (lines do not have any event at all).
4.2 - As the user clicks anywhere on blank space of detail section near top left of target line, it is accompanied by automatic detection of that line. In confirmation, a red marker appears at top left of the line. Dragging the mouse (with left button pressed) on form detail section leads to induced movement of line identified by the marker.
4.3 - Similarly, when the user clicks anywhere on blank space of detail section near bottom right of target line, it is accompanied by automatic detection of that line. In confirmation, a red marker appears at bottom right of the line. Dragging the mouse (with left button pressed) on form detail section leads to induced resizing/rotation of line identified by the marker.
4.4 - Rotating action on a line can be carried out in either direction (clock-wise or anti clock-wise). There is no limit to the angle of rotation. So long as left mouse button is kept pressed, the user can continue rotating the line in complete circles in either direction.
Note: It is observed that combo box and list box do not behave in a completely satisfactory manner while being dragged or re-sized through direct use of mouse events of these controls. There is no such problem with induced drag/re-size approach, as demonstrated in styles B to D. Interestingly, styles C & D are completely non-intrusive and do not depend upon any event of target control.
You can find the sample here: http://www.rogersaccesslibrary.com/forum/Form-dragdropresizearrange_topic596.html
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