R – Scrolling Dialog in MFC on Win CE / Windows Mobile

mfcscrollwindows-cewindows-mobile

I'm building a dialog based Windows Mobile application.
My main container dialog has a tab control which alternates between different child dialogs (as separate tab sheets).

As I have limited display real-estate I need my dialogs to scroll vertically.
Following some online example, I added a vertical scroll bar, and the appropriate message and handler to deal with vertical scrolling.

The scroll bar itself behaves perfectly, changing it's position when I click on it or drag it. My dialog however remains static and doesn't scroll.

To isolate the problem, I modified the scroll message handler and hard-coded a ScrollWindow() command whenever a scroll occurs, like so:

void SettingsDialog::OnVScroll(UINT nSBCode, 
    UINT nPos, CScrollBar* pScrollBar)
{
    ScrollWindow(0,30,NULL,NULL);
}

The code is reached, but still no scrolling occurs in my dialog.
Can anyone shed some light on this mystery?

By the way, i've found a thread on Coding Guru which discusses the exact same problem, but has not been resolved here: http://www.codeguru.com/forum/showthread.php?t=54304

Best Answer

I've run across the same problem. I never use MFC, but the Win32 function to make it work correctly is this:

         ScrollWindowEx(hDlg, 0, currentPos - si.nPos, NULL, NULL, NULL, NULL, SW_SCROLLCHILDREN | SW_INVALIDATE);

Related Solutions

C++ – Moving between dialog controls in Windows Mobile without the tab key

I don't know MFC that good, but maybe you could pull it off by subclassing window procedures of all those controls with a single class, which would only handle cases of pressing cursor keys and pass the rest of events to the original procedures.

You would have to provide your own mechanism of moving to an appropriate control, depending on which cursor key was pressed but it may be worth the usability gains.

If that worked, you could enumerate all dialog controls and subclass them automatically.

Windows Mobile 6 allows switching between dialog controls using cursors by default - it's a new, more "smartphoney" way of moving around the UI and it's incredibly convenient.

Javascript – How to check if element is visible after scrolling

This should do the trick:

function isScrolledIntoView(elem)
{
    var docViewTop = $(window).scrollTop();
    var docViewBottom = docViewTop + $(window).height();

    var elemTop = $(elem).offset().top;
    var elemBottom = elemTop + $(elem).height();

    return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}

Simple Utility Function This will allow you to call a utility function that accepts the element you're looking for and if you want the element to be fully in view or partially.

function Utils() {

}

Utils.prototype = {
    constructor: Utils,
    isElementInView: function (element, fullyInView) {
        var pageTop = $(window).scrollTop();
        var pageBottom = pageTop + $(window).height();
        var elementTop = $(element).offset().top;
        var elementBottom = elementTop + $(element).height();

        if (fullyInView === true) {
            return ((pageTop < elementTop) && (pageBottom > elementBottom));
        } else {
            return ((elementTop <= pageBottom) && (elementBottom >= pageTop));
        }
    }
};

var Utils = new Utils();

Usage

var isElementInView = Utils.isElementInView($('#flyout-left-container'), false);

if (isElementInView) {
    console.log('in view');
} else {
    console.log('out of view');
}

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