I am using a window that uses a subclass of NSView. Part of it is drawn when the program starts, another part needs to be drawn when the user clicks on a button in another window. The code for the other window calls my subclass of NSView with no problems, creates the new graphics, and then returns. However, the window that needs to get updated with new graphics does not change.
When I put both the beginning graphics and the graphics that are to be drawn later in the initial drawRect call everything is drawn without a problem. However, drawRect does not get called when the user clicks the button on the second window. I've tried awakeFromNib, setNeedsDisplay, needsDisplay, and display, but nothing I've found so far gets the NSView window to call drawRect.
I am fairly new to OS X programming and appreciate any hints you can throw my way.
Thanks, Tom Jeffries
You should separate button click into a controller class and that controller should call setNeedsDisplay on view object. Don't say view itself setNeedsDisplay.
Related
You can see the video of the problem below. When I press the Minimize button, the screen disappears, but when you put the other window on top without pressing the Minimize button, the screen will not be covered and it will always float on top. This problem did not occur in Windows 7, but it occurs after upgrading to Windows 10.
Problem video
I would like to know the DirectX initialization code for the function or function argument related to this problem. (As far as I know, this game uses DirectX 9.)
Additional Information
Based on Castorix's advice, I used the Spy ++ program to test it. Below is the result screen.
The problematic program consisted of two windows, a parent window and a child window. The parent window style consists of WS_CAPTION, WS_MINIMIZE, WS_VISIBLE, WS_CPLISIBLINGS, WS_SYSMENU, WS_OVERLAPPED, WS_MINIMIZEBOX, WS_MAXIMIZEBOX, 0x00008000. And the child window style consists of WS_CHILDWINDOW, WS_VISIBLE, WS_BORDER.
Additional Information 2
If you look carefully at the above video, when the game window goes under the notepad window, the game title bar is hidden, but you can see that the game screen is always on top instead of just being covered.
I'a currently working on a small utility, it's my first ever X project. The utility is used to draw a small circle around your mouse pointer. I use an app called Pinpoint to do the same on my Mac, it helps me find my mouse as I'm visually impaired.
The utility creates an transparent X window and draw a circle inside, it then moves that window with the mouse pointer so that the circle follows the mouse.
It currently works, except for one detail. Mouse events are not propagated up to the underlying windows. Basically, the utility makes the mouse useless.
As far as I can tell from the Xlib docs, if not otherwise specified, new windows should propagate all events. How can I fix this?
The code can be found on GitHub: https://github.com/blubber/circle-cursor it's a bit messy currently, becaue it is just a proof of concept.
I would suggest doing via cursor image as well, there are many ways when you won't be able to receive mouse events and only possible source would be polling with XQueryPointer.
With xfixes extension you can subscribe to all cursor image changed events and get most recent shape of the cursor, and whit XRender you can set your own ( possibly animated cursor )
I am trying to make a MFC SDI application in VC++ to draw different shapes on click of the respective button. We have written our code inside the OnDraw() function. But Ondraw gets automatically called on running the application. We want it to be called only on the onclick of respective button. How do we proceed..?
When a shape button is clicked set a member variable that remembers what you want to draw.
Call Invalidate. This will cause OnDraw to be called by the framework.
In OnDraw check the member variable and draw the shape.
You must permit OnDraw to draw every time it is called by the framework. That is how the window image is restored after being uncovered, unminimized, resized, etc.
You cant prevent that OnDraw is only called when you press a button.
OnDraw in a view is called when WM_PAINT arrives and asks the window to repaint itself. Not executing OnDraw would cause nothing to be drawn at all.
OnDraw is also called when your application is minimized and maximized again, or when the size of the window changes.
Also I can not think about a scenario, where I want drawing only when a button is pressed. You need to be more precise. here.
OnDraw, as xMRi said, is called by the framework ... but if you want to draw something only when you click on a button, why don't you create a member variable, setup when you click the button, and get count when OnDraw is executed ?
void CYourAppView::OnDraw(CDC* pDC)
{
// MFC code
if(m_bButtonWasClicked)
{
// draw what ever you want
}
}
I have developed a game but this is a serious problem I am facing. I don't have any threads in my code , but whenever I use alert
Display.setCurrent(my_alert)// my_alert has a timeout of 3000ms
then after this alert, a blank white screen appears.When the screen is pressed, then my game canvas reappears. Before setting alert, my game canvas of checkers board is set as the current display. This problems also appears after the automatic keypad lock.
This alert is vital for my game, Kindly suggest a solution.
Issues like that typically indicate missing or incorrect override of GameCanvas method showNotify():
The implementation calls showNotify() immediately prior to this Canvas being made visible on the display. Canvas subclasses may override this method to perform tasks before being shown, such as setting up animations, starting timers, etc. The default implementation of this method in class Canvas is empty.
Above method is invoked at return from Alert to prior screen. GameCanvas should somehow trigger repaint of the the screen (eg using repaint or flushGraphics methods), otherwise it will be displayed blank.
The fact that this problems also appears after the automatic keypad lock makes it even more likely that showNotify is not done right in your MIDlet.
I have an application that displays a CFrameWnd that is displayed on top of the main window. I need the window to be non-movable and non-resizable when the user selects a certain mode for the window.
My CFrameWnd is created with the styles WS_OVERLAPPEDWINDOW | WS_THICKFRAME | WS_POPUP
I have come across a solution using an overload of CWndOnNcHitTest to rewrite
HTLEFT,HTRIGHT,HTTOP,HTTOPLEFT,HTTOPRIGHT,HTBOTTOM,HTBOTTOMLEFT,HTBOTTOMRIGHT,HTSIZE,HTCAPTIONto HTBORDERto prevent the framework to recognize the areas responsible for sizing / moving.
This method works well for resizing in my case, but moving the window is still possible, although the hittest override works correctly (verified with traces).
Is there anything wrong in my approach, or could there be something interfering with this solution and if so, do you have any tips on where to look?
You should be able to make OnNcHitTest() work, don't return HTCAPTION.
Still, there's more than one way to move/size a window, you also have to worry about the system menu (type Alt+Space). Write a message handler for WM_MOVING and WM_SIZING and override the RECT so the window stays put.