Last edit: 05-03-17 Graham Wideman


GWDropDemo and GWDragDemo Release Notes
Article created: 98-07-04

Issues and Notes

Date Version Note
98-12-21 1.13 Release Release of 98-11-19 mods.
98-11-19 not released yet Revised GWMonOLE unit declaration and implementation of IUnknown.QueryInterface to return HResult so it compiles in both D3 and D4.  Thanks to Carlos Augusto Grahl for pointing this out.
98-10-02 1.12 Release
  • Revisions to GWDropDemo and GWDropTarget:
    • Corrected use of ReleaseStgMedium
    • Improved logic for drop-effect handling
    • Corrected note on drop effect handling, and IE behavior, here.
98-07-29 1.1 Release Packaged GWDropDemo, GWDragDemo, GWRefCt and associated source code and docs for distribution.
98-07-28 GWDragDemo V1.1 Initial release version of GWDragDemo completed.
98-07-20 GWDropDemo
  • Version Changes:
    • Factored OLE monitoring functionality into separate form unit, disentangling it from monitored objects and application windows.
    • Fixed bug in TGWDropAppInterface.Drop_StdEffect that had caused it to erroneously return "LINK" action if either Shift or Control was active (should only return LINK if both are active).
    • Moved Reference tests and Temporary Drop Disable to Test menu
    • Changed default Drop_StdEffect so that it agrees with Windows default behavior.  Added "Test Safety" options to GWDropDemo to compensate.
      Note: not all drop sources actually delete after a drag-move, and some do so only after drag to particular targets.  MS Word is an example of app that DOES delete after drag-move.
    • Added File -- Save Formats and Data function.
98-07-20 GWDropDemo
Dieter Steinwedel discovered that GWDropDemo doesn't have a way to accept drops from the Recycle Bin. That turns out to be because RB will ONLY collaborate with a MOVE action, which GWDropDemo V1.0 doesn't support.
98-07-04 GWDropDemo
Ye Chen was the first to point out that GWDropDemo appears not to accept drops of URLs from Internet Explorer (I tried IE3.02).   Turns out this is not quite true:

a) GWDrop Demo will accept drops from IE's "Organize Favorites" window, no problem.

b) If you drag hyperlinks from a web document in IE's main window, then you have to hold down the Shift key to get GWDropDemo to accept them.  This is because IE approves a "move" drag effect, but not a "copy" drag effect. 

According to the MS SDK docs the supposedly "normal" interpretation of drag with no modifier keys is "move". However, a "move" operation has the side effect that a source application may delete the object that it "moved" to the destination, which we probably don't want during testing.

Therefore, with no modifier keys, GWDropDemo V1.0 is written to propose a "copy" effect.  In my opinion, not approving "copy" is a bug in IE, since clearly you ar not moving the hyperlink, you are copying it.

However, this suggests in future versions of GWDropDemo I should provide a "normal" and "safe" checkbox to switch between behaviors.

98-07-04 GWDropDemo V1.0 To do: it would be good to add "Clear" button to force empty of format list and data contents.


Go to:  Drag and Drop Intro Page, or  wideman-one