Borderless Window Using Areo Snap, Shadow, Minimize Animation, and Shake

Question

I am making a application with a borderless window on Windows. However, since the window is borderless, I have no areo shadow, snap, minimization animation, or shake. I have looked around and found no site that explains how to implement this. However, I know it is possible because Office 2013, Visual Studio 2012, and Steam all have these features and are borderless. I am specifically using QT and C++ but if you have solved this for another windowing library I would like to hear your solutions as well. either. And by areo shadow I don't mean drop shadow on two sides, I mean the glowing shadow on all sides of all active native areo windows applications.

Salvage

I read up on DWMWA_ALLOW_NCPAINT. So word 2013 and VS2012 draw OVER the boarder to hide it? – Salvage

Many people are looking for the answer on this question, as I see. I was one of them a while ago. I tried the implementations, already answered in this post and for reasons they are not fit perfectly. After some time of googling and modifying the deimos1877's BodrelessWindow sample, i ended up with more lightweight solution for Qt. This is simple Qt project with just QMainWindow. Feel free to use and adopt it for your needs. The main advantage is - no proxy classes between Qt window and native WinAPI, no window title flickering through with Aero off. bitbucket.org/artem_bodrin/framless – Prettify

Answer 1

After using Spy++ to inspect Steam's window (its window styles, how it replies to window messages) and trying to match everything it does, combined with the DWMAPI calls from this C# borderless window behavior, I believe I figured it out.

To hide the window's border, handle the WM_NCCALCSIZE message in your WindowProc:

case WM_NCCALCSIZE: {
    if (window->is_borderless) {
        return 0;
    } else {
        return DefWindowProc(hwnd, msg, wparam, lparam);
    }
}

To enable the shadow, all you need to do is:

MARGINS borderless = {1,1,1,1};
DwmExtendFrameIntoClientArea(hwnd, &borderless);

To turn it back off, restore the default margins MARGINS windowed = {0,0,0,0};. Perhaps throw in a SetWindowPos(hwnd, 0, 0, 0, 0, 0, SWP_NOZORDER | SWP_NOOWNERZORDER | SWP_NOACTIVATE | SWP_FRAMECHANGED | SWP_ASYNCWINDOWPOS | SWP_NOSIZE | SWP_NOMOVE ); also, to make sure the frame gets redrawn.

However, this does not seem to work with all window styles, apparently your window style must not contain a titlebar. Title bars work fine, and adding one seems to enable the minimize animation.

The simplest window style I got the shadow to work with was WS_POPUP | WS_THICKFRAME, to also get aero snap, maximizing, minimizing, and the smooth minimize animation I used WS_POPUP | WS_THICKFRAME | WS_MINIMIZEBOX | WS_MAXIMIZEBOX | WS_CAPTION.

Changing DWMWA_NCRENDERING_POLICY or DWMWA_ALLOW_NCPAINT via DwmSetWindowAttribute does not appear to be required, the default settings seem to work.

One word of caution: DwmExtendFrameIntoClientArea does exactly what the name suggests, so if you are drawing an image with an alpha channel directly into your client area (say with opengl, direct3d/2d), a small frame will be visible through it:

So you might have to put a non transparent widget, brush or something behind the transparent element.

If all goes well, it should then look like this:

Here is a small example project, F11 toggles borderless/windowed mode, F12 toggles the borderless shadow on and off.

Intramuscular

Steam still has a shadow identical to that of Aero. It has Aero Snap/Shake/Stuff too, but lacks a minimize animation. – Poly

@RandomUser My solution does everything except the minimizing transition - a result of the window style required to make the shadow work. Even Outlook 2013 lacks this, so I do not believe it is possible without faking it like Visual Studio does its glows. (sometimes you can see the window frame becoming visible inside the "client" area - so they do indeed appear to draw over the frame) – Intramuscular

Visual Studio's minimize animation seems to look exactly like a window with a border. Did they just do a really good job faking it? Any idea how we could go about faking it as well? – Poly

It looks that way. I think it'd be a lot of effort just to get the minimize animation, though - you won't get the aero shadow; you'll have to draw your own shadow/glow instead of the frame. Also, there could be lots of special cases to handle to maintain the deception of the border not being there. Say, making sure that Alt+PrintScreen only captures the client area and not the frame, window size for aero snap (so there is no gap because of the see-through border)... – Intramuscular

Everything except the minimize animation, I think. – Intramuscular

@Intramuscular I can't seem to get this to work, can you please upload your project files so we can see this in action. That would be really helpful Thank you so much. – Lit

@Poly I was wrong about the title bars, if you add WS_CAPTION to the style you will get the minimize animation as well. – Intramuscular

@Intramuscular Thank you so much! I have tried running it on VS2013 RC and has some small issues. So I went ahead and opened an Issue on Github and we can hopefully continue this conversation there. – Lit

@Intramuscular Do you mind if we use some of your example code (For Now) in our open source application? – Salvage

@Salvage not at all :) – Intramuscular

@Intramuscular I got it worked :) But I can't see the control buttons. does it come with the titlebar itself ? Can I show the control buttons with those configurations ? – Mosemoseley

@Mosemoseley there was some window style which would show the buttons even in borderless mode, check the comments in my code where I define the styles. they don't look pretty though, you'd be better off drawing your own. – Intramuscular

Answer 2

Thanks to melak47 for your answer.

For people whom are looking for a C++/Qt example, this GitHub profect does the job like a charm (thanks to deimos1877) based on melak47 code! https://github.com/deimos1877/BorderlessWindow

Be sure to use visual studio compiler (>= 2010) to get the needed DLL and it should work. This example include aerosnap support, borderless window, minimize effect, aero shadows.

Verbal

I'd like to say, this is the best answer, hope new people comes to here to use this demo. – Previse

With Qt5.8 you get a compiler error in qwinhost.cpp in line 257 complaining about not found qWinAppInst() identifier. qWinAppInst() has been removed from QtCore in Qt5.8 (see here) so you have to replace that one with GetModuleHandle(0) – Ridenour

Answer 3

I have created one that responds as photoshop.

BorderlessWindowQt-Modern-Gui

Delorisdelorme

I did not say the downvote, I just want to tell you that the links should only be supportive, because if the link is broken, your answer becomes useless – Bethune

GPL2. I prefer to implement my own. – Saidel

It works perfectly and if anyone has the opportunity to improve it and more. He is welcome. – Delorisdelorme