How can change alphablend of a form without affect on control in form?
Delphi XE7
One solution to this problem is to use Multi-Device Application (if using VCL is not possible).
If you need to leave a transparent TForm just changing a property Transparency = True.
If you need to leave a semi-transparent component, all components have the Opacity property that can be assigned a more transparent value between 0 and 1, where 0 is closer to that component.
For example you could put the controls within a TLayout and change the Opacity of it as you see fit, and have no effect on the other components, or vice versa.
Actually the answer to this might be pretty simple...(for windows only)
The JEDI VCL library has a component (TJvTransparentForm) that allows you to take an Alpha blended PNG image (ie the gray background shown in your picture above) and use it to make a form control. The picture is actually stored in a TImage and you would need to place your "Icons" on the image itself. Then just respond to the mouse clicks on the TImage.
You have what your asking for (maybe?).
If you were tricky enough you could probably even track the mouse movement and change the Image to glow the correct "button" that the mouse was over.
Related
I have recently converted from Image Lists to Virtual Image Lists and Image Collection controls. All my images are stored in the TImageCollection as png files with transparency. They render fine on the toolbar tool buttons but these same images are not rendered as transparent images with TMainMenu. Do I need to render all menus using Owner Draw?
Embarcadero only add the TImageCollection and TVirtualImageList components (the old component does not change). Lot of old components do not call the DoDraw method from the TImageList or TVirtualImageList component (almost each use own method for transparency). Even the components calling the DoDraw method from TImageList don't always work correctly (problems with styles).
They also use 'outdated' methods for transparent images (do not use alpha blending almost in all old components).
I make own descending components (transparent image, speed button, toolbar, tree view, tabcontrol), TImageCollection and TVirtualImageList. But not the TMenu component (use only my version of TImageCollection and TVirtualImageList) because TMenu calls the DoDraw method from TImageList/TVirtualImageList for drawing icons.
I think Embarcadero must change drawing pictures in components. They need call DoDraw method from TImageList/TVirtualImageList in all components with pictures.
I am trying to create a basic map editor for fun which consists of a scrollbox and paintbox (to draw the grid).
In the OnMouseDown event for the paintbox I create images at runtime and add them inside the scrollbox, the grid paintbox is painted above the images ( because if the grid was at the back it just would not look good ).
Here is a sample screen:
My question would solve two of my problems in one.
I need to be able to drag and drop (to move) the images around at runtime.
I also need to be able to get the X and Y position of the image to display as information.
Here is where my problem lies, to solve the problems above I first need to get the Image under the mouse cursor. But because I paint my grid (paintbox) above the images, the cursor will only ever 'see' the paintbox grid, and not the underlying images.
I did experiment with copying the paintbox grid to a TImage but it came out all wrong and I was getting out of memory errors. The size of the maps could be quite large and so putting the grid onto a bitmap is not ideal due the memory and limitations etc.
The grid must go on the top, otherwise it would look something like this:
Which hides the grid, and I don't want that to happen.
So, how can I see past the paintbox and get to the images underneath, using FindVCLWindow or something similar?
Set the Enabled property of the PaintBox to False. That will let the mouse messages go through.
Further:
In the OnMouseDown event for the PaintBox I create images at runtime and add them inside the scrollbox
Change that to the OnMouseDown event on the ScrollBox. Adjust the coordinates by ScrollBox.[Horz/Vert]Scrollbar.Position.
Is there any way to make a control transparent like button, edit, panel or etc...? I mean something like opacity or alpha blend that we have in form property.
Some components have the transparent property. In others you can choose 'none' as the color property. It differs from component to component, but not all components can be made transparent by changing a property.
You should try googling Delphi transparent components, there are downloadable components and tricks you can do to make existing components transparent.
Take a look at the Win32 windows styles, especially WS_TRANSPARENT (or WS_EX_TRANSPARENT).
Applying transparency on a child control can be done very easily using old-fashioned regions and the SetWindowRgn() function.
Applying alpha blending on a child control, on the other hand, is very difficult to do prior to Windows 8. It involves painting the parent window to a bitmap first, then alpha blending an image of the child control on top of the bitmap, then rendering the bitmap onscreen.
In Windows 8, the WS_EX_LAYERED window style (which is what Tform's TransparentColor and AlphaBlendValue properties use internally) has finally been implemented for child controls.
I have a form with an image as the background.
Now I need to put several transparent dark color areas in several areas off the form.
I need not to hide the background. How can I do this?
Standard Delphi control do AFAIK not support that kind of transparency. You therefore have two possiblities:
use third-party components
create your own component (you can derive from an existing one) and override the paint method. In the paint method just draw the correct part of the background image and darken every pixel to get the effect you want.
You can try Delphi 2009/2010 which supports using PNG images. The PNG image format allows for alpha layer transparency, which it sounds it what your looking for. This assumes that your wanting a fixed shape on your form.
EDIT-- For Delphi 2007, you can attempt to use the PNG Components which if I remember correctly do properly handle alpha transparency.
Is the background image and the darker areas the only thing that you want on your form, or do you have other components that should be blended too?
If it's only the background image and the dark areas, I would recommend that you check out Graphics32. It's an image control supporting layers. It should be fairly easy to archive what you want (or what I assume that you want...) from that.
When a new TImage is created it is transparent. After drawing objects to this image I would like to clear them. Note that I need to keep the image transparent as the TImage is being used as an overlay to another image.
Some sort of "clear" function for the TImage would be best. I think I'm missing something simple here, I just could not find any clear function within the TImage menu.
You're not really meant to draw things on a TImage control. You're meant to assign its Picture property and leave it alone. In fact, when you draw on a TImage, you're either drawing transiently by drawing on its Canvas property, or you're modifying the underlying Picture object by drawing on its canvas.
To clear a TImage, simply unassign the Picture property.
Image.Picture := nil;
To draw transient images — something you'll need to repaint whenever the window gets obscured and revealed — use a TPaintBox.