I have a filmstrip of images in png format like this:
I'd like to know how to clip each of the images and put these images in a TImageList control, always preserving the transparency.
[EDIT]
Yes, at designtime the trick mentioned by RRUZ works fine, but I wanted to clip the images at runtime, i.e. by loading the filmstrip from resource or file
You must follow these steps:
set ColorDepth property to cd32Bit,
DrawingStyle to dsTransparent,
Height= 48,
Width=48,
then load the image and the result will be
Just import into the imagelist. It'll complain that it's too big and offer to break it into pieces for you. Works fine for me on D2005.
Another cool tip: I use AWIcons Pro http://www.awicons.com/icon-editor/ to edit icons (nice editor!). It has a feature that can export an icon as an imagelist (.bmp or .png format), thus making the filmstrip out of an icon. This makes it really handy to edit these things in .ico format, with a series of cells all the same size and depth, with each cell varying slightly. Then you export as an imagelist (I use .png) and then Delphi can break them back out into individual cells. Very slick. AWIcons isn't free, but features like this really make it productive.
At runtime, you would have to call TImageList.FileLoad. Except it won't work.
This in turn calls ImageList_LoadImage, with uFlags parameter value including the bit LR_LOADFROMFILE, which causes Windows to load from a file on disk. This underlying functionality only supports TBitmap (BMP) format.
See the nearly-duplicate question. PNG support is a designtime feature that is converting the PNG data into an internal non-PNG and not-exactly-a-BMP-either format, used internally by MS Common Controls library. View your DFM as text, and you will see what your PNG inputs have been turned into. The other answers show you that transparency is preserved, using bitmap-color based transparency.
If you want to keep your data in PNG format, you shouldn't be using a VCL TImageList to store it, because you're going to have to do a conversion from PNG to TBitmap to actually use TImageList.
Related
I have read this article by Paweł Głowacki and I have been able to display an icon for my component. The result is the following:
I can see the image in the Tool Palette and in the structure view. By the way in the designer I see the default icon:
How can I display the icon of my component in the designer as well?
I am using Delphi Tokyo 10.2 Update 2. I have followed the article I have linked to get the image shown. My component is the following:
type
TEquationSolver = class(TComponent)
//code...
end;
Basically, I have done the following:
I have created 3 bitmaps (16x16 24x24 32x32) and a png (128x128)
I have added them as resources going into Project > Resources and Images
I have called them TEquationSolver with the suffix that indicates the size. In this way they are properly displayed on the IDE.
What am I missing for the design time part? In this article I have read the following:
Our guide is: Use PNG if you want very easy backwards compatibility,
or small file (BPL) size; use bitmaps if you want fast loading. We
use bitmaps for 16, 24, and 32px icons, and PNG for the 128px icons.
In fact I have 16x16, 24x24, 32x32 bitmaps and the 128px png. Is there something else?
It seems that you have to create the files I have shown above plus the image for the Designer. The latter needs to match the name of the class that inherits from TComponent (in my case):
As you can see I have added another bitmap (it's the 32x32, I have just made a copy and changed the name) and I have used TEquationSolver as name. After a Build + Install I have the following result:
Note that I could have added only logo.bmp as resource (with the ID that matches the TComponent-derived class name) and it would have worked anyway. The problem is that the pictures won't be neat because they'll be resized and they may appear blurred, like in my case.
For this reason I think that it's good:
Put an image that will appear in the form designer
Put the 16x16, 24x24, 32x32 and 128x128 that will be used by the IDE
The difference is evident in my case. When I have only a single bitmap the quality of the image is low but when I provide the various sizes they look better.
In Delphi XE2, I have a JvGIFAnimator component (from JVCL) on a form. Now, when I run this program on a computer where the Windows DPI Display Settings are set to 125%, while all other GUI elements and system text are scaled up to 125%, the GIF animation unfortunately is not resized. The GIF is embedded in the JvGIFAnimator component with the TJvGIFAnimator.Image property at design time as a TJvGIFImage.
Is there a way to rescale the embedded GIF at run-time according to the Windows DPI Display Settings?
You'll have to do this yourself one way or another. There is nothing built in that will automatically rescale. Options include:
Decode each frame of the GIF. Use a graphics library to resize the images. Create a new GIF with the resized images.
Provide multiple GIFs at different sizes and use the one with size closest to the target.
Of these options, the latter is better. Resizing on the fly will lead to horrid visual artifacts and aliasing. Your animation will look dreadful. Not to mention all the coding involved. Choose option 2.
In fact, this issue is no different for rasterized animations as it is for rasterized static images. Just as you need to provide multiple glyphs for toolbar buttons, you need to supply multiple versions of your rasterized animations.
Delphi 2010's TSpeedButtons did not seem to really support PNG transparency properly, because the Glyph property uses a TBitmap internally, and TBitmap is for bitmaps, and doesn't support PNG transparency properly, and TSpeedButton.Glyph can't support transparency then.. update: But the actual problem was that I had some external stuff (Developer Express components) that was rendering delphi's PNG support non-functional, TImage on the other hand, while it still TPicture, and can support PNG, was also affected by this Developer express bug.
A question was already asked about here, and the answer shows how to use pre-blending so that transparency won't turn into black pixels. I want to know if there is another button control that will use alpha-blended PNGs loaded at designtime, and which does not convert the PNG resources into BMP format discarding the alpha channel and, causing the black border shown here.
In short, this control would not use TBitmap, and would not use the color key transparency feature that is all TBitmap has.
To repeat, I am not asking how to solve the black-around-the-outside issue while still using the out-of-date TBitmap/TSpeedButton based VCL functionality, because it lacks modern PNG transparency functionality, I am asking about replacing it with something else that "just works".
As a secondary drawback, converting a small .png file into a .DFM bitmap resource is essentially wasting space and making my form .DFM content too large. Native .png file format storage within the .dfm should make the resulting forms smaller.
Update: PngComponents look like they should work, but I got an Invalid Graphic format error when I try to load a png into the Png speedbutton. Note that the Png image list component has no such problems. It seems that cxLibrary (a developer express package) is breaking things. Once I removed all developer express stuff, this problem goes away. So although I have selected Pngcomponents as the answer, if you have devex stuff installed, use their buttons instead, and not pngcomponents.
You may have a look at PngComponents. It has a TPngSpeedbutton and some other controls working directly with PngImages.
You could also look into the TMS Software Component called TAdvGlowButton as this supports PNG images with alpha transparency.
Link to site...
It turns out that cxButton that comes in the Developer Express VCL component pack also supports PNG buttons.
How to get a TPicture from a TImageList?
I need to do Image1.Picture:=...TPicture from an image list, to load an image into a TImage.
An image list stores all my PNG images that are transparent.
I tried to use a bitmap (GetBitmap), but what I need is transparency. Unfortunatelly, I have a white background using a bitmap.
Thanks!
The regular TImageList uses bitmaps. Although they can be partially transparent, it is actually just a fake. In Delphi you can draw bitmaps to be transparent by assigning them a single transparent color. That exact color will be drawn a 100% transparent, while the other colors are not. Usually the color is taken from the bottom left corner of the image.
TPicture itself doesn't do anything. It is merely a container for TGraphic descendants. You'll have to find a type of image that can be transparent.
A convenient format is PNG. PNG event supports an alpha channel, which means that every pixel can be assigned a different transparency value.
Fortunately there are TPngImageLists that combine the ease of TImageList with the power of PNG. You can read this article. It is in Dutch, but maybe Google Translate can help you. Or maybe you can find an english resource on this subject. I've used this imagelist and it's great, because you can have actual icons with an alpha channel and still use them with regular toolbars and speedbuttons.
Running Turbo Delphi Pro.
I'm using TImage to display a png image.
When I restart Delphi and load the dpr file, TImage is still there, but the picture is lost,
requiring a reload of the picture before compiling.
At first I thought it's a path issue, so I loaded the picture from the same directory as the dpr, but it didn't help.
What else can I try?
Try this:
Open your project and your Form with
the PNG.
(Re)Load the PNG image.
Save and close your Form.
With a text editor, load your Form
DFM
I bet you don't have a big binary in
your TImage object, because the PNG content
has not been saved.
Bottom line, you'd have to include it as a resource and load it dynamically at runtime.
I ran into this problem as well with D2006. The solution I used is similar to François'.
I have a TPngImageCollection component that I collect all the images in at design time. You will need to find unit PngImageList off the web. The TPngImageCollection component has the advantage that you can have a collection of PNG images of differing sizes.
At run-time on startup, I assign the TImages from each of the collection members:
Image1.Picture.Assign (ImageCollection.Items [0].PNGImage) ;
Image2.Picture.Assign (ImageCollection.Items [1].PNGImage) ;
Image3.Picture.Assign (ImageCollection.Items [2].PNGImage) ;
etc
Bingo - you can produce your PNG originals with alpha transparency (I use PhotoPlus 6.0 from Serif - free and very capable) and show them in a TImage.