How to make WebBrowser control with transparent background? - c++

I try to make my WebBrowser control transparent, so if the HTML loaded into it has no background, the underlying window should be visible.
I`ve broke my head trying different ways.
There is a transparent background in Microsoft Sidebar application. In gadget`s HTML <g:background> tag can be used, but this tag is not available in usual webBrowser control.
I`ve also investigate in DirectX Transform filters, which can be applied to the HTML elements in IE, but have no success.
Any help would be greatly appreciated.

WebBrowser (aka Internet Explorer) has no such capabilities. You'd have to host it in a window that uses the WS_EX_LAYERED style flag and use SetLayeredWindowAttributes() to make the color key match the background of the displayed HTML. Avoid displaying any text, it is going to look bad when the anti-aliasing pixels no longer blend the letter with the background.

Related

How to change button color?

I am developing a GUI application using Embarcadero VCL c++ IDE for windows OS. As part of this project, I have to change color of button with respect to an external state.
I understood that windows32 API will not allow to change the color of button.
Could you please suggest me, how to change button color?
Do you wish to change the background-colour of the button, or the text-colour of it?
Since windows has used visual themes for some time now, if you have commctrl loaded and include a manifest file, the button will be drawn using the default (current) theme.
Options I can see include (a) custom-drawing the background (b) changing the text-colour in the normal draw process (c) drawing the button without a theme (i.e drawing a 'flat' button).
You could simply draw a bitmap-button, changing the bitmap depending on the state of the button. You could also use a single bitmap, tinting it using the HSL or HSV colour-space, depending on the state.
As for the flat type of button, I think you can probably change it's background-colour in much the same way as you can change the colour of the text - by intervening during the standard draw process and changing the colour from 3D_FACE (or whatever it is, I forget) to whatever you'd like.
If you look at the calculator included with windows XP, you can see an example of changing the text colour.
CodeProject.com likely has a stack of articles that would help in this endeavour. :)

win32 c++ owner draw button with transparent image

i've implemented a owner draw button into my win32 app (no MFC). The button is a normal 20x20 bitmap (round icon with transparency). The problem is that the button is positioned on a solid background and i can see the buttons gray background (since the bitmap is round). I've tried responding to WM_CTLCOLORBTN with NULL_BRUSH but no luck.. I've tried displaying the button using a bitmap and a ico file but wont budge.. Does anyone know how to solve this problem?
This is my problem, the settings icon should be transparent at the edges (not white/gray)
It sounds like you're trying to make a non-rectangular control.
You could call SetWindowRgn to tell Windows that your control is non-rectangular.
In addition to what #joel's answer, if you want to make some area transperant put a unique color in the area where you want to have transperancy using some image editors (RGB(0xFF,0x00,0xFF)) is mostly used Then use TransperantBlt
You say it's a solid background but your image shows some kind of orange-yellow gradient as a background. If it really was a standard windows button solid color you can load the bitmap with LoadImage using the LR_LOADMAP3DCOLORS or LR_LOADTRANSPARENT. Since you have a gradient you'll have to use a more complicated technique to mask out the bitmap.
http://www.winprog.org/tutorial/transparency.html

Is is possible to make a shaped, alpha-blended dialog?

I'm making a non-rectangular dialog, modelled over an image from Photoshop (the image is the background of the dialog, and the user will see trough the transparent part of the image). I'ts like a dashboard-style window for a media-app with a few custom-drawn controls. Most of the background-image is either opaque or 100% transparent - but in between there is a thin area of partially transparent pixels, ment to blend the image smootly into the background. This works great for web-graphics, but I have not found a way to make this work for Windows windows. I'm using the Windows Template Library (WTL), msvc 2008 - and the app must run on Windows XP as well as Vista and Windows 7.
Currently, I'm simply using the opaque part of the background-image to create a GDI clipping-region, but this gives pretty rough edges.
Does anyone know about any API functions to accomplish this (part of WTL, or reachable from WTL)?
Perhaps you could use layered windows? I haven't tested these with WTL but you should be able to get the effect you want. To the best of my knowledge I don't think you can add controls to a layered window so you'll need to attach it to another (non-layered) window to use controls.
Not sure how this interoperates with WTL, but have a look at the AlphaBlend function. You'll need to select your partially transparent bitmap into a DC and copy that to your dialog's DC in your paint function.
This article shows how to use layered windows with WTL and the Gdi+ API which is available on all your target platforms.

Screen capture of MDI app with OpenGL graphics using MFC

In our MDI application - which is written in MFC - we have a function to save a screenshot of the MDI client area to file. We are currently doing a BitBlt from the screen into a bitmap, which is then saved. The problem is that some of the MDI child windows have their content rendered by OpenGL, and in the destination bitmap these areas show up as blank or garbled.
I have considered some alternatives:
- Extract the OpenGL content directly (using glReadPixels), and draw this to the relevant portions of the screen bitmap.
- Simulate an ALT+PrtScr, since doing this manually seems to get the content just fine. This will trash the clipboard content, though.
- Try working with the DWM. Appart from Vista and Win7, this also needs to work on Win2000 and XP, so this probably isn't the way to go.
Any input will be appreciated!
The best way to get a bitmap from an OpenGL window is to draw the content to a bitmap 'window'. See PFD_DRAW_TO_BITMAP for more information on how to do this.
If you want to go with the Alt+PrtScr way, you have to consider that many users have their own print screen tool installed which reacts on that very same hotkey. So you can't be sure that this hotkey will copy the content to the clipboard. It may just open the window of the installed print screen tool/utility.
Use the glReadPixels() approach. This question is asked quite often, here, on the gamedev.net forums and on other places, so google should show you code samples easily, but the glReadPixels() approach is the generally recommended approach.
Simulating keypresses is a recipe for disaster, I would stay away from that.

Win32: How can i set the color of windows Title, Scrollbar etc.?

I am updating a GUI of a Win32 Application in white text on black background. Thats simple for my content. But how can i change also the color of my child windows (Titlebar, Scrollbar etc.). i Know there is WM_CTLCOLORDLG to set the color of Dialogs. I also know there is WM_NCPAINT, but that would leave all painting (i.e of Scrollbars) to me. All i want, is to set colors of my choice.
You can use SetSysColors() to change the colour for window captions, borders, etc. (see http://msdn.microsoft.com/en-us/library/ms724940(VS.85).aspx). However this will change the colour for all windows, not just yours, so it is at the least an unfriendly thing to do.
One option is to use SetSysColors() to change the active window caption colour when your application has focus and to reset it to the defaults when it loses focus. But I'd say that's klunky and not really in keeping with good practice (suppose your application crashes? and there might be some flickering).
WM_NCPAINT is there so that you can do things like this. It is a bit of a pain, but maybe that's to discourage you from creating non-standard windows... ;-)
Hook GetSysColor() (Using something like Microsoft Detours)