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IntroductionIf you use Nero Burning Rom to burn CDs and DVDs, you will without a doubt have noticed the "progress" indicator at the bottom of the compilation window. It shows how much of the disc space is currently used, and it is green as long as the files fit the disc. Depending on the settings, it becomes yellow and then red when the compilation files become too large to fit the available disc space. I needed a bar like that for my current application, but couldn't find any that possessed the features I required. I did, however, find an article called "Vista Style Progress Bar" - author unlisted - that showed me how to make a very nice looking progressbar. It doesn't look like Nero's space indicator at all, but I was only interested in the color functionality anyway, so it doesn't matter a bit that the bar itself is much nicer looking. The above link is for a "normal" progressbar, and even though it features three different colors, only one of them can be used at a time. And its value span is hardcoded to a value between 0 and 100. The Work I Did InitiallyI used the code which was originally in C# to make a similar control in VB.NET 2005. First of all, I fixed two bugs in the control (value out of range check was done incorrectly and the control crashed when value was set to 0). Then I added a lot of stuff:
New in Version 1.3The one thing I was really not content with was the color handling. I adapted the code from the original progressbar control, but it is not optimized to say the least. Every time you want to add a color, you have to add a lot of code. I would rather that the user could choose the colors freely instead of having to depend on the colors that are defined in the control. The problem is that in order to paint a colored segment, the control uses FOUR different shades of that color. Let's say that the user chooses the color " I had absolutely no idea how to do that, but luckily I got a code sample from "Four13 Designs" in the message forum. It takes a given color and calculates a lighter or darker color using a correction factor on all three color components. Great, I thought - I can just use the colors that are already defined to find the correction factor for the three color shades I needed to calculate. But it turned out that I couldn't do that. The original colors didn't have the same correction factors for the different shades, and they didn't even have the same correction factor between the three RGB components of the same color. What was I to do? I wanted the "new and improved" control to look the same as the old one with the fixed color definitions. So I didn't want to dabble around with the correction factors myself and possibly create a control that looked different from the original. I saw no solution to the problem, but I still wanted the user to be able to select the colors freely, so in the end I said "ah, what the f..." and using the old and beproved trial and error method, I came up with correction factors that worked for me, and - as far as I can see with the naked eye - produced colors very similar to the original colors. My biggest problem was solved. Please note: The Some other major changes in the new version are: In version 1.2 I introduced a progress percentage text property. I show the value of the NeroBar in percent in the bar. It dawned on me after I published the version that if you use the color segments to indicate a "too large" value like in Nero, then a percentage based on the entire width of the control would not be correct. Let's say you have the So in this version, I've introduced a new property For the same application I made this control for, I needed some kind of count down indicator. I thought: Why not use the NeroBar for that too. I wanted the bar to start at max an then count down to 0. At a given point, I wanted the bar to change color to indicate that the countdown was almost over. So I couldn't use the bar right off with different coilor segments. Instead I implemented a mode where the whole bar changes color when a threshold is passed (Property: These new properties are demonstrated in the demo application as well. Just click the buttons at the bottom and check out the animation. A Brief DescriptionThere is really not much to explain: The properties are all shown in the demo application, but for giving information, I'll list the properties you will want to know about here:
When you use the demo application, please note that there is no validation of the values, so it will be possible to set the properties to values that the NeroBar will not accept - thus generating an exception. It is merely provided to demonstrate the functionality of the control - not to be a 100% failsafe application. Possible ImprovementsI'm done now! I really have no more ideas how I can improve this control. If anybody can think of something, please let me know. The only thing I could wish for is some kind of ruler or scale below or in the bar to help determining the progress. I'm going to have a look at that possibility, but rather than incorporating it into this control, I think I'm going to make it a control of it's own. We'll see. History
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