My application is screenshot maker. User needs to select screen area to make a screenshot. I use Win32 API with PureBasic, but it doesn't matter, all is similar with C++.
When user runs application, the semitransparent borderless form is shown on full screen to hook mouse over all other windows. On mouse down event selection is started and I apply XORed region to the form to cut a hole in it with size of current selection.
I create and apply a new region on every mousemove event:
rgn1 = CreateRectRgn_(0,0,DWidth,DHeight) ; full size of desktop
rgn2 = CreateRectRgn_(sx, sy, ex, ey) ; current selection points
CombineRgn_(rgn1, rgn1, rgn2, #RGN_XOR)
SetWindowRgn_(WindowID(0), rgn1, #True); apply region
It works well on my computer with Windows XP, but works buggy on other computer with Vista. I think it is wrong when I create the new region object on every mouse move. Maybe I need to create it once and then to resize? Can anybody explain how to do this right? Examples on C++ are ok.
In the beginning you create region, using CreateRectRgn (like in your code).
Then it's enough to call SetRectRgn function for updating region bounds
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What I am trying to do is to determine when another application is clipping the mouse cursor. I am using SetWindowsHookEx(WH_MOUSE_LL,...) to detect mouse movement. I could test the mouse position against its previous position every time my WH_MOUSE_LL callback is called, but this wont work if any of the sides of the application's window are touching the edge of the desktop as windows itself is also clipping the cursor.
More specifically, I am writing a program that overrides the default mapping of the virtual desktop when there are multiple monitors. I have everything working except in the case where a fullscreen application is running and constraining the mouse to its window. I cannot distinguish between the cursor actually trying to exit the side of the screen or if the current in-focus application is clipping it.
Is it possible to tell weather the in-focus app is clipping the mouse or maybe to prevent windows itself from constraining the cursor within the desktop, allowing the aforementioned check to work? Is there some other solution that I am missing?
Thank you.
Ah, I'm an idiot. GetClipCursor(RECT*) will do the trick.
first off, I'm very new to using API's so please bear with me I'm on a steep learning curve !
I'm creating an application using Silverfrost Fortran FTN95.
I've been trying to initiate the opening of an initial Window within the program which uses the whole screen
useable area (the so-called WORKAREA in API parlance) but am having a problem.
Having used GET_WINDOW_LOCATION# API function within my Fortran code to obtain the dimensions and origin of the max possible area for
the window (without taskbar), I've then defined the 'origin' of the window to be at -n,-n where the border is n pixels thick and I've
increased the window dimensions by (2xn) in each direction so that the other 2 borders will be off-screen at top or under the taskbar at the bottom edge).
Anyway, I'm having difficulty obtaining exactly the same as produced via clicking the 'MAXimise button' on a window.
While the window produced itself seems to occupy the whole area available, when it appears the CAption appears right on the upper edge of the
CAption ba(i.e. not centre justified vertically).
Also, the MINimise, MAXimise and CLOSE buttons in top rh corner of window do not fill the whole depth of the CAption bar (they're about half the depth and indeed appear to be cut-off).
If I subsequently click the window 'MAXimise button' after initial window creation then the CAption and buttons re-align themselves correctly.
This is all illustrated in this image here:-
http://s1164.photobucket.com/user/john_pbucket/media/SilverfrostForumsImageFiles/MAXWIN-Summary_zpscajfx3vx.png.html
Note - I first created the full window with borders within the available screen area (this is the first example shown) where the window Border (8pix wide) is visible
The subsequent attempt to create the window as per the MAXimise button places the window at origin (-8,-8) and I increase the window dimensions by 16 (2xborder width) in each direction in order to get the borders off-screen, but thy're still there.
So, What series of Windows API commands should I be using exactly to get the window to open in a correctly maximised state, and are there any 'subtleties' of alignment and/or spacings I should be aware of which may be causing this problem?
I guess the question boils down to 'what sequence of API commands does the window MAXIMISE button execute ?' but I can't find an answer anywhere.
Maybe there are also some subtleties I need to know about with regard to any windows dimensions parameters which could be creating the anomaly ?
Any help/guidance would be appreciated. Thanks
I am trying to capture windows hidden behind my application. I am using windows 7 and VC++. I have tried printwindow() function which draws the both non-client and client area of hidden window, but captured window in the device context doesn't show desktop composition effects(aero effects). Instead it shows the captured window with windows 7 basic theme.
I have also tried with GetWindowDC() to retrive the DC of hidden window, and then Bitblt() it to memory DC but the captured window doesn't show non-client area (caption, close button, minimize button etc) correctly.
Anybody faced this issue?
Please help.
Click the link below. It leads to a MSDN site that lists all the existing Windows Functions ever of all history since Windows 95 up to Windows 8 (from period where Microsoft started Windows until present). It shows old windows functions of first Windows and new windows functions added for the new windows.
http://msdn.microsoft.com/en-us/library/windows/desktop/ff468919(v=vs.85).aspx
Anyway follow this site.
You will see the name of each function as a link.
Click any of them that you are interested.
Each link there leads to another MSDN site that explains all the basics knowledge that you must know about the function before using it, that you want to learn more. What that function does, its purpose, all its parameters and how to use each one, all their flags, all parameters types, return value and at last remarks section that shed more light and sometimes gives tips about the selected function.
Of course, you don't have to read all of them. Find in the list only the necessary functions to fit your needs. The functions that will solve your problem and answer your question that you posted.
By the way, I read your post, and I think that I found in the list the necessary functions that will do what you want to do, I will list them below, and say in one sentence what each does for what you need:
AnimateWindow - Enables you to produce special effects when showing or hiding windows. There are four types of animation: roll, slide, collapse or expand, and alpha-blended fade.
FlashWindow - Flashes the specified window one time. It does not change the active state of the window.
FlashWindowEx - Flashes the specified window specified number of times. It does not change the active state of the window.
Use these functions to achieve the aero effects that you want.
SetWindowPos - Changes the size, position, and Z order of a child, pop-up, or top-level window. These windows are ordered according to their appearance on the screen. The topmost window receives the highest rank and is the first window in the Z order.
Use this function to show the hidden windows on the top side (above all other windows) and on the screen front of you. The operating system will automatically draw the both non-client and client area of these windows without using any gdi, draw and paint functions yourself.
If you want these windows to return back to their previous state (where they were hidden), then save their state with GetWindowPlacement function and later call SetWindowPlacement to bring them back to their hidden state. You can try GetWindowRect and SetWindowPos instead to achieve the same goal.
I also think that you will be interested in GetWindowTheme and SetWindowTheme functions and all the draw theme functions (BackgroundEx, Edge, Icon, Text, TextEx).
There are more theme functions. Find in msdn and in other sites on the web.
I'm looking to simulate a kiosk mode for Safari on Windows. OSX will not work with my input hardware and Chrome's GPU acceleration is too slow for the machine I'm using.
The only plausible solution [so far] is to run Safari and send an F11 (fullscreen) keystroke, but prevent the URL bar from expanding when the mouse reaches the top pixels of the screen.
I've looked and can't seem to find any good solution and would like to know if I can restrict the cursor movement from reaching the top pixel of the screen?
If anyone has any other solutions, that would be great!
You can use the ClipCursor function to do this.
Confines the cursor to a rectangular area on the screen. If a subsequent cursor position (set by the SetCursorPos function or the mouse) lies outside the rectangle, the system automatically adjusts the position to keep the cursor inside the rectangular area.
You can poll the cursor position and correct it using a timer, but this is not ideal. You could also cover the top bar by a transparent topmost window. This way, input will never reach the top bar.
EDIT: If Internet explorer is an option you have the possibility to use the COM object to embed what you need in a custom application. Other browsers might have similar APIs, but I'm not familiar with them.
I have been all over the web looking for an answer to this, and my question is this:
How does a GUI framework work? for instance how does Qt work, is there any books or wibsites on the topic of writing a GUI framework from scratch? and also does the framework have to call methods from the operating systems GUI framework?
-- Thank you to any one who takes the time to try to answer this question, and forgive me if i misspelled anything.
In the old days we did a lot of GUI programming from scratch. It is not as hard as it seems, but it requires a few weeks to come with results.
First you need a good drawing library. Minimal functionality for this library is drawing clipped rectangles (using patterns), lines, bitmaps, and fonts. You can cheat by creating fonts as bitmaps, and clipped rectangle is just a bunch of horizontal lines.
Now you need at least drivers for mouse, keyboard, and timer (if not already provided by the operating system). In general, you will need to detect keys, symbol keys (such as shift, etc.), mouse moves and mouse clicks. Basic timer functions will allow you to detect double clicks.
Then you need to create a window data structure. This data structure needs to have coordinates i.e. a rectangle, link to parent window (if not top window), and window function i.e. the function that will be called when this window should handle some events.
Once you can draw on screen you need some rectangle algebra functions. You need at least good function to calculate intersection of rectangles, and a quick resolution of relative to absolute coordinates. For example - if your child window has parent then its' x and y should recursively be added to parent x and y until you reach top window.
At this point you have your:
- primitive graphical functions,
- window structure,
- mouse driver, keyboard driver, and timer,
- rectangle arithmetic.
Now you can write your main event harvesting function. This function will run all the time. It's purpose will be to detect events and send messages to correct windows. What is an event? Well, when you start your program, store mouse x and y coordinates. Then in a loop check if they have changed. If they have changed, find the window at that position ... and send WM_MOUSEMOVE event to it. Your harvesting function should handle:
- mouse moves
- mouse clicks
- mouse double clicks (remember last click and position, measure time and decide if it is a double click or not)
- timer events
- keyboard buffer changes
...
Now you should be able to send events to windows. But you really need a mechanism for it. It is a combination of message queue, and window procedure. It usually works like this: each window has a window procedure which commonly accepts four arguments: message id (i.e. is it mouse move, is it paint message), window handle, parameter 1 and parameter 2. You can call this window procedure directly using something like a send_message functions. Or you can send this window a message via post_message function. This will put message to the queue and window will process messages one by one, eventually receiving this one. So why should you call one messages directly and put others to the queue? Because of priority. You see, a keyboard click can wait some time before being processed. But a window redraw must complete immediately to prevent flicker and wrong data on screen.
So your harvest_events function sends messages to windows using post_message, and send_message. And your window message pump gets them using typical message pump like this:
while (pmsg = get_message() != NULL) send_message(pmsg->id, pmsg->hwnd, pmsg->p1, pmsg->p2);
get_message simply obtains message from the queue, and calls send message. Simple, huh? Well, not quite so. This way you would only receive driver messages to windows, but you also need some functions to redraw windows, move them, etc.. When you create move_window function, resize_window, show_window, and hide_window function, your window coordinates will change. Parts of other windows will be uncovered (if top window is moved or closed).You need to calculate which windows are affected by coordinate changes and send paint message to those windows (to repaint only the parts that were uncovered - remember, you have clipping drawing functions so this will work).
These functions introduces messages msg_paint, msg_move, msg_resize, msg_hide...
Last, you need to maintain hierarchy of windows. Your top window should be the desktop. It should have child windows (application top windows). These windows may have further child windows (buttons, edit boxes, etc.) The obvious structure for holding these is the window tree. When you detect mouse click you have to traverse window tree and do it in a smart way (finding out who has focus, who is modal, etc.) to send message to the right window. And when you draw you also must traverse all children to see who is uncovered and who is not. Last but not least, you need to handle mouse rectangle as top window to prevent flickering the mouse as windows are re-drawn or (using timers and msg_paint events) animated.
That's roughly it.
A GUI framework like Qt generally works by taking the existing OS's primitive objects (windows, fonts, bitmaps, etc), wrapping them in more platform-neutral and less clunky classes/structures/handles, and giving you the functionality you'll need to manipulate them. Yes, that almost always involves using the OS's own functions, but it doesn't HAVE to -- if you're designing an API to draw an OpenGL UI, for example, most of the underlying OS's GUI stuff won't even work, and you'll be doing just about everything on your own.
Either way, it's not for the faint of heart. If you have to ask how a GUI framework works, you're not even close to ready to design one. You're better off sticking with an existing framework and extending it to do the spiffy stuff it doesn't do already.