Mouse progress control

• Download demo project - 60.5 Kb
• Download source and release DLL - 20.6 Kb

Introduction

This article introduces a mouse progress control that follows the mouse. The solution is based on global Windows hooking and it uses a DLL that is dynamically imported to the application.

Background

I have created several applications and utils that process a lot of information. Usually it is time consuming and the users have to wait. I used to create a popup window with a progressbar to indicate the wait time; sometimes the GUI itself contains the progress. After a search for a better solution someone suggested to set the mouse cursor with the hourglass. The hourglass is a good idea, but I wanted it to show a progressbar.

I tested two solutions for the "problem", the first solution was 100 mouse cursors that contained the mouse and a progressbar. That solution did work, but several users complained that their "fancy" cursor changed to my dull cursor-look. The second solution was to hook the system and create an owner drawn progress control that followed the mouse. And that resulted into this article.

I'm just finishing off a new version of SizeMe and the music mode part of the program takes a while since it: reads each mp3-file ID-tag, indexes it, sorts it, and then groups it. That process takes time and the user had to have some feedback on that. Since SizeMe has a clean GUI I thought this would be a great idea. That is the main reason why I created this control in the first place, but hey I love to share.

Layout

I'm more of a programmer than a designer. But I did create 2 out of 3 designs in this control. Here are the three floors:

• Smooth

  

  This style looks like the default progress control with PBS_SMOOTH option on. It is plain looking and it is possible to add a percent text on top of it.

• Mac

  

  This style is much more good looking. The idea and design is originally made by Paul M. Meidinger ("Macintosh-like Progress Control"). It uses degrades of the selected colors. In addition, here it is possible to add percent on top of it.

• Round

  

  This little puppy is my "masterpiece". Inspired by the Mac-control & some progress bars I saw in games I decided to create a round-looking-progressbar. It is possible to customize at which angle it should start and end, plus the width of the progress fillings.

Using the code

The Mouse progress class uses a DLL which sets a system wide hook. That does "not" mean that you need to add the .lib-file to the project because the DLL is dynamically loaded. To implement the code into your existing project, you only need to add these files:

• MousePrg.cpp
• MousePrg.h
• MousePrgVars.h
• MousePrgHook.h

And copy the MousePrgHook.dll file to where the executable file is.

You should create the class on the heap and delete it when you're finished. (Remember since it uses a hook, the DLL will load into each program that is active after execution, and it does not need to be active when not in use!). A typical usage of it could be like this:

//Class defs

CMousePrg *pMProgress;
//(...)


//When you start a time consuming process (this is an MFC example, 

//on win32 you usually have the instance/hwnd handles)

pMProgress = new CMousePrg(AfxGetInstanceHandle(), this->GetSafeHwnd());
//(...)


//While you are moving along processing your stuff

pMProgress->SetPercent(nPercent);

//Delete the progress when you're finished.

if(bFinished==TRUE)
{
    delete pMProgress;
    pMProgress=NULL;
}
//(...)

The CMousePrg class inits the hook and start drawing the progress. It will show until you delete the object. It is meant to be that way, so you are "forced" to delete the class and the hook get detached. (Many hooks might slow things down, I guess).

Defaults

The defaults are listed in the MousePrgVars.h header file. Here is the list of the defaults and the choices that are available:

Known issues

I haven't found a good way to detect if a HWND is a context menu or not. There have been several attempts to detect that, but with no success. I wanted the progressbar to be hidden while a context menu was opened. That way it wouldn't slide in the background while you select. I've tried to catch the WM_INITMENU and WM_EXITMENU messages but the WH_GETMESSAGE hook does not seem to catch those. Any suggestion on this problem would be great!

Another problem is when a message queue inits a modal dialog that locks the parent queue. In those cases you have to run the Hide() function to quickly hide the progress.

Points of Interest

System wide hooks are a cool feature, but it has some challenges along the way. I wanted the mouse progress control to work on many different instances at the same time. But that does not work when the DLL-file is named the same. It seems to me that Windows is so "smart" that a DLL-file loaded twice with the same name does not get loaded a second time. I did some searching and found different solutions to the problem. Earlier on I did use the BASS Sound SDK. Ian (the programmer of BASS) handled different instances of the library by copying the file with a unique name, and then loaded it. That worked for me too, and the system is hooked once per instance created by the class.

History

• v1.0 - First public release