Closing old window when opening a new one in Cocoa - cocoa

Ok, I have two windows, A and B. When I click a button on Window A, I want it to close and take the user to Window B. makeKeyAndOrderFront does a great job of activating Window B, but how do you get it to then close Window A?

Send window A a close or performClose: message (depending on whether you want to emulate the user closing the window, which is the latter, or simply close it immediately and unconditionally).
Note that closing the window may release it; see the releasedWhenClosed property, which has a checkbox in IB and may already be turned on there. You may want to order the window out (as compared to ordering in, such as by ordering front) instead.

Related

Save and Restore Pane-Specific Information in DockPanelSuite

So I have looked through existing answers tagged with dockpanel-suite and have not found what I am looking for (as I type this, it is also not appearing in the Similar Questions area). For starters, note that I am NOT asking about saving and restoring the entire Workspace.
So here is the scenario. I have a graphical window (we will call it "Timeline") that is added upon user request. When it is added, it is automatically docked to the bottom-most area of the main form. The user then takes the Timeline window and redocks it somewhere else (could be docked to an edge, or within another docking pane) and changes its docking behavior (floating, auto-hide, tab, etc.).
A demonstrable example is in Visual Studio. If you have the Solution Explorer on a tab within an docked pane on the right and close Solution Explorer, you can go to View -> Solution Explorer and bring it back up again, and it restores to the correct location.
Now the user closes the Timeline window entirely by hitting the [x] on its pane, and in the future, they request to add it to the application again. I want to bring it back in the last dock state and position it was in when it was last closed.
Now, I appear to be able to catch the closing of the pane with the ContentRemoved event, but in there e.Content.DockHandler.Pane, e.Content.DockHandler.PanelPane and e.Content.DockHandler.FloatPane are all null so I have no obvious way to get the previous dock geometry. e.Content.DockHandler.DockPanel is valid, but it is the parent/root docking panel, and calling SaveAsXml(...) does nothing for me because it would get the entire workspace.
Even if I were able to capture it here, information I need. However, I do not appear to be able to simply call LoadFromXml(...) on anything either.
If I try to do it before the DockContent object is added to the DockPanel, DockHandler.DockPanel member is null, so I appear to have no place to restore the XML into, even if I was able to get it.
There are no other events hanging off of DockPanel that seem to be able to help me here.
So - is there a way to do this, and what is the correct way to do it? I want to make sure I am not barking up the wrong tree with trying to capture the dock information as XML when closed and restore it later.
I have toyed with the idea of not actually closing the window but just undocking and hiding it, but have not explored that very far yet. Same with hooking the DockChanged event, but it does not seem to fire on the DockContent objects being docked/floated/etc. and I am not sure why.
Also the solution needs to be robust enough so that I can correctly handle scenarios such as if the last docking parent no longer exists. For example, if it was docked as a tab somewhere, but now that parent window (containing the tabs) has also been closed. I do not know if LoadFromXml, presuming it is the right way to do, is robust enough to handle this scenario, as I have not been able to test it yet.
If I understand the question, what I do is to trap the Closing or FormClosing event, .Hide() the form and set e.Cancel = true. If you are using DockContent, then there is a HideOnClose() that does the work for you. Then when you want to "re-open" the window, you simply use an empty .Show(), and it will Show right where it was when you "closed" it.
As far as saving if the last docking parent no longer exists, I agree with Lex Li, that will take a hack.

Winapi: window is "sent to back" when using EnableWindow() function

To prevent users from clicking in my main_window when a MessageBox appears I have used:
EnableWindow(main_window,FALSE);
I got a sample MessageBox:
EnableWindow(main_window,FALSE);
MessageBox(NULL,"some text here","About me",MB_ICONASTERISK);
EnableWindow(main_window,TRUE);
The problem is that when I press "OK" on my MessageBox it closes and my main_window is send to back of all other system windows. Why this is happening?
I tried to put:
SetFocus(main_window);
SetActiveWindow(main_window);
after and before : EnableWindow(main_window,TRUE) the result was strange: it worked 50/50. Guess I do it the way it shouldn't be.
Btw.
Is there a better solution to BLOCK mouse click's on specific window than:
EnableWindow(main_window,FALSE);
Displaying modal UI requires that the modal child is enabled and the owner is disabled. When the modal child is finished the procedure has to be reversed. The code you posted looks like a straight forward way to implement this.
Except, it isn't.
The problem is in between the calls to MessageBox and EnableWindow, code that you did not write. MessageBox returns after the modal child (the message box) has been destroyed. Since this is the window with foreground activiation the window manager then tries to find a new window to activate. There is no owning window, so it starts searching from the top of the Z-order. The first window it finds is yours, but it is still disabled. So the window manager skips it and looks for another window, one that is not disabled. By the time the call to EnableWindow is executed it is too late - the window manager has already concluded that another window should be activated.
The correct order would be to enable the owner prior to destroying the modal UI.
This, however, is only necessary if you have a reason to implement modality yourself. The system provides a standard implementation for modal UI. To make use of it pass a handle to the owning window to calls like MessageBox or CreateDialog (*), and the window manager will do all the heavy lifting for you.
(*): The formal parameter to CreateDialog is unfortunately misnamed as hWndParent. Parent-child and owner-owned relationships are very different (see About Windows).

How to stop event propagation despite WS_EX_NOACTIVATE?

I have a semi-transparent form (using AlphaBlend) that acts as an overlay. For the user to still be able to interact with the window below I have set WS_EX_NOACTIVATE on my form so all right and left clicks go through to the other window.
However I have a few clickable labels on my form. Clicking those and performing the appropriate action works fine since despite the WS_EX_NOACTIVATE flag the OnClick methods are called, but the click will (obviousely) also propagate to the other window, which I do not want in this case.
So, does anyone know how to "stop" the click being sent through to the window below in case I already handled it in my form ? Basically I would like being able to chose whether the click "belongs to me" and does not get propagated or whether the window below mine receives it.
As Rob explained, WS_EX_NOACTIVATE is not relevant here. Most likely you used WS_EX_TRANSPARENT and that made your window transparent to mouse clicks.
To get finer grained control of mouse click transparency, handle the WM_NCHITTEST message in your top level window. Return HTTRANSPARENT for regions that you want to be "click through". Otherwise return, for example, HTCLIENT.
Wm_ex_NoActivate should be irrelevant here. That just controls whether your window receives the input focus. Indeed, if you start with a scratch program and do nothing but change the extended window style, you'll see that when you click within the bounds of that program's window, the clicks are handled in the usual way, except that the window is never activated; programs behind that window do not receive any click events.
Therefore, to make your label controls eat click events instead of forwarding them to the windows behind them, you need to find out what you did to make them start forwarding those messages and simply stop doing that, whatever that is.

On Windows, should my child window get a WM_WINDOWPOSCHANGED when its z-order changes relative to one of its siblings?

I am trying to insert a custom widget into the Internet Explorer 8 url bar, next to the stop and reload buttons. This is just a personal productivity enhancer for myself.
The "window model" for this part of the IE frame is an "address bar root" window that owns the windows which comprise the IE8 url bar: an edit box, a combo control, and the stop and reload buttons.
From another process, I create a new WS_CHILD window (with a custom class name) that is parented by IE's address bar root window, thus making it a sibling of the edit box and stop/reload. I call SetWindowPos with an hwndInsertAfter of HWND_TOP to make sure it appears "above" (i.e. "in") the urlbar. This works nicely, and I see my window painted initially inside the IE urlbar.
However, when I activate the IE window, the urlbar edit control jumps back in front of my window. I know this is happening because I still see my window painted behind the urlbar, and because when I print ->GetTopWindow() to the debug console on a timer, it becomes the HWND of the urlbar edit control.
If I update my message loop to call SetWindowPos with HWND_TOP on WM_PAINT, things are better -- now when I activate the IE window and move it around, my control properly stays planted above the edit control in the urlbar. However, as soon as I switch between IE tabs, which updates the text of IE's urlbar Edit control, my control shift backs behind the Edit control. (Note: This also happens when I maximize or restore the window.)
So my questions are:
1) Is it likely that IE is intentionally putting its urlbar edit control back on top of the z-order every time you click on a tab in IE, or is there a gap in my understanding of how Windows painting and z-ordering works? My understanding is that once you specify z-ordering of child windows (which are not manipulable by the end-user), that ordering should remain until programmatically changed. So even though IE is repainting its Edit control upon tab selection whereas I am not repainting or otherwise acting upon my window, my window should stil remain firmly on top.
2) Given that the z-order of my window is apparently changing, shouldn't it receive a WM_WINDOWPOSCHANGING/WM_WINDOWPOSCHANGED? If it did, I could at least respond to that event and keep myself on top of the Edit control. But even though I can see my window painting behind the urlbar Edit control when I click on a tab, and even though my debug window output confirms that the address bar root's GetTopWindow() becomes the HWND of the Edit control when I click on a tab, and even though I see WM_WINDOWPOSCHANGING/WM_WINDOWPOSCHANGED being sent to the Edit control with an hwndInsertAfter of HWND_TOP when I click on a tab, my own window receives no messages whatsoever that would allow me to keep the z-order constant. This seems wrong to me, and addressing it would force me to run in IE's process and hook all messages sent to its Edit control just to have an event to respond to :(
Thank you for your help!
It's quite likely that IE is juggling the Z-order of the controls when you change tabs. In IE9, the URL bar and the tabs have a common parent. When you select a new tab, it activates the URL bar (and activation usually brings the window to the top of its local Z order).
No. You get WM_WINDOWPOSCHANGED when a SetWindowPos function acts on your window. If some of the siblings have their z-orders changed, you don't get a message. Nobody called SetWindowPos on your window. You can see this by writing a test program that juggles the z-order of some child windows.
This makes sense because there might be an arbitrary number of sibling windows, and it could be an unbounded amount of overhead to notify all of them. It also would be nearly impossible to come up with a consistent set of rules for delivering these messages to all the siblings given that some of the siblings could react by further shuffling the z-order. Do the siblings that haven't yet received the first notification now have two pending notifications? Do they get posted or dispatched immediately? What if the queue grows and grows until it overflows?
This is different from WM_KILLFOCUS/WM_SETFOCUS notifications in that it affects, at most, two windows. That puts a reasonable bound on the number of notifications. Even if there's a runaway infinite loop because the losing control tries to steal the focus back, the queue won't overflow because there's only one SetFocus call for each WM_KILLFOCUS delivered.
Also, it's reasonable that windows might need to react to a loss of focus. It's much less likely that window C needs to know that B is now on top of A instead of the other way around, so why design the system to send a jillion unnecessary messages?
Hacking the UI of apps you don't control and that don't have well-defined APIs for doing the types of things you want to do is anywhere from hard to impossible, and it's always fragile. Groups that put out toolbars and browser customizations employee more people than you might expect, and they spend much of their day probing with Spy++ and experimenting. It is by nature hacking.

Hide window until the top window is displayed

I am facing a little annoying design problem. Not easy to give a title of my question.
I must display two windows, one over another one. The first one is a Cocoa window, the second is made with Qt. In the second window, an action is performed, but the user can choose to close this window. He must fall back on the first window.
To display my first window, which is actually a SFAuthorizationPluginView, I do:
[myview displayView];
then, to display the window made with Qt on top of first window:
QWidget* w = openMyScreen();
NSView* v = (NSView*)w->winId();
[[v window] setLevel:2003];
This works well, however there is a small delay before the second window is displayed. We can thus see for a very short time the first window.
I need that the second window stays on top of the first window, because the user can close the second window and must have access to the first window.
Any ideas on a trick how to hide the first window, just the time, the second window appears?
Thanks in advance
NSDisableScreenUpdates and NSEnableScreenUpdates (link) might be useful in this situation. The documentation says:
You typically call this function so that operations on multiple windows appear atomic to the user.
which seems to describe your situation.
A word of unrelated advice though: Don't go setting window levels willy-nilly. A window level of 2003 will likely cause the window to appear over things like the dock or even the menu bar, which would definitely be strange. You should stick to the standard levels declared in NSWindow.h unless you have good reason. NSFloatingWindowLevel might be appropriate (although I'm not sure what level the SFAuthorizationPluginView window is displayed at).
Starting with MacOS 10.4, you can use :
[NSWindow disableScreenUpdatesUntilFlush];

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