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c#mshtml

How to change position of caret in MSHTML during mouse click?

I have a MSHTML-based control embedded in an application and the ContentEditable mode is used to edit documents inside it. The body of the HTML document initially contains the following lines:

<div></div>
<div id="signature"></div>

The caret is placed at the beginning of the document, that is inside the first DIV element. Now when user clicks with mouse inside the control in a place below the last line, the caret is moved into the second DIV element, as it's the closest one to the point where the user clicked.

I want to move the pointer to the end of the first DIV on the mouse click. Now I have the code to calculate the intended position of the caret as IMarkupPointer and IDisplayPointer. What I need to know is where to intercept the MSHTML event pipeline to do the actual caret move.

I've written code that implements IHTMLEditDesigner and moves the caret using IHTMLCaret.MoveCaretToPointer to the intended position. The problem is that no matter where I intercept the event (PreHandleEvent, PostHandleEvent or PostEditorEventNotify) the caret position is eventually reverted to the default one on single click (but it is not reverted if I hold the left mouse button pressed for a while or if I click with right mouse button).

Solution

  • Use jscript inside of the HTML that you load into the IE control. If you do not know HTML and jscript very well you will find this task very painful.

    See these questions for my experience when I tried do so something like this.

    I also had lots of other problem, including have to write resize logic in jscript to get the HTML editor to size along with the WinForm form and having to pass the default form/coontrol colours into the HTML editor so that it looked write then users changed colour schemes on Windows.

    Even better just find a HTML editor and load it into the IE control, you will still have to code with standard window colours etc yourself.

    There are also 3rd party winforms HTML editors you can use. If possible I think you should buy in a solution as ContentEditable is a lot harder in real life then it look.

    A quick google found.