Let's say I have a floating, borderless, circular NSWindow.
It is circular because the content view simply draws a red circle.
That content view needs to be layer-backed ([contentView setWantsLayer:YES]), because I'm applying CoreAnimations on it, e.g., animated scaling.
Usually, the clickable area of a NSWindow is defined by the transparency of the pixels of the content view. However, once the content view of a NSWindow becomes layer-backed, transparent areas will also receive clicks, unfortunately.
In my case, this is a serious problem, because I only want to receive clicks within the radius. But now, a click within the rect of the window, but beyond the circle radius, will activate the window (and thus, the entire app), which it shouldn't. Also the window is draggable via the corner of its content view.
My initial thought was to implement [NSWindow sendEvent:] in a subclass and check whether the click was performed within the radius, using [theEvent locationInWindow]. I thought I could simply discard the event, if it's beyond the radius, by not calling [super sendEvent:theEvent] then. This however did not work: I noticed, that the mouseDown:; window method is called even before the sendEvent:; method.
I've search a lot but the only idea I found, was to have a proxy like non-layer backed NSWindow on top of the window, which delegates clicks conditionally, but this led to unpredictable UI behavior.
Do you guys have any idea, how to solve it?
So after a few weeks, I came to the following results:
A) Proxy window:
Make use of a non layer-backed proxy window, which is placed on top of the target window as a child window. The proxy window has the same shape, as the target window, and since it is not layer-backed, it will properly receive and ignore events. The proxy window delegates all events to the target window by overwriting sendEvent:. The target window is set to ignore all mouse events.
B) Global Mouse Pointer observation:
Install both a global and local event monitor for NSMouseMovedMask|NSLeftMouseDraggedMask events using addGlobalMonitorForEventsMatchingMask and addLocalMonitorForEventsMatchingMask. The event monitors disable and enable ignoring mouse events on all registered target windows based on the current global mouse position. In the case of circular windows, the distance between the mouse pointer and every target window must be calculated.
Both approaches work well in generally, but I've been experiencing some unpredictable misbehaviors of the child window approach (where the child window is 'out-of-sync' of its parent's position).
UPDATE: Both approaches have some significant disadvantages:
In A), the proxy window sometimes may be out of sync and may be placed slightly off the actual window.
In B), the event monitor has a big impact on battery life while moving the mouse, even if the app is not the front-most application.
If you want to Discard mouseDown event based on position you can use the:
CGPathContainsPoint(path,transform,point,eoFill):Bool
Setup your path to match your graphics. Circles, ellipses, rectangles, triangles or paths and even compositional paths (paths with holes in them).
Related
To keep things simple, let's say I have a window containing a single view, which has auto layout constraints binding all 4 sides to the window container view with offset 0. And assume that this view also has a constraint setting its aspect ratio to a constant value. If I resize the window manually, then then window nicely maintains the desired aspect ratio. But if I click the little green zoom widget, then the window fills up the whole screen, regardless of the aspect ratio, with part of the view being above the top of the screen. Is there some way I can make zooming resize the window as big as it can be, without violating auto layout constraints?
I couldn't very well detect this problem in the delegate method windowWillResize:toSize:, because that doesn't tell me which screen it's thinking about putting the window on. I could try to fix the window size in the windowDidResize: delegate method, at which time I do know what screen it's on, but I'm not sure exactly how to do that without reinventing Auto Layout's wheel.
Apparently someone thinks I wasn't explicit enough, so I'll try again. Steps to reproduce:
In Xcode, create a new macOS App project using XIB interface.
Open MainMenu.xib and select the window.
Reshape the window to be approximately square.
Using the Attribute Inspector, set the Full Screen behavior for the window to Auxiliary Window.
Drag an Image View from the library and drop it in the window.
In the Attributes Inspector, set the image view to show the NSComputer image and scale axes independently.
Expand the image view to fill up the window content area.
With the image view selected, click the button to add new layout constraints.
Add 5 constraints, binding the 4 sides to the container, and setting the aspect ratio. (see screen shot)
Build and Run.
Observe that if you resize the window by dragging an edge or corner, the aspect ratio remains fixed.
Click the green zoom widget in the title bar of the window, and observe that the window expands without regard for the aspect ratio constraint, cutting off part of the image.
I just set up a test project exactly as you specified, and when I invoke the window zoom widget, the window expands and retains its aspect ratio i.e. it works as expected. The only thing I can think of that might be causing your issue: maybe your content hugging and content compression resistance priorities are at odds with your constraints? Mind you, I just left them at the default values and it worked fine. Unfortunately Mac/AppKit development (esp. when using IB) is rife with these kind of odd bugs and weird behaviour, probably because Apple has not given it any love in years, so bugs creep in/fester and they are clearly so DONE with developing UI the 'old fashioned way'. (Using SwiftUI to make a Mac app is just as frustrating, in different ways, so I'll stick with what I know). FYI, I used Xcode 13.4.1 to create this test project. Good luck!
Let's say we have two screen scenario and a NSWindow,
positioned at the edge of screen 1.
A part of that of that window is also shown on screen 2.
What I would like to achieve, is to draw the window only on screen 1 and to not show the rest on screen 2.
The reason for that is that's some kind of a specially behaving mini window, not a usual one.
Is it possible to assign a certain NSScreen to draw the window on, only?
Two very different approaches:
Use Mavericks: What you looking for sounds like the behaviour of Mavericks' "screens have separate spaces" mode. In this mode a window is never drawn on two screens except during drag operations, at other times the window is draw on one screen with any areas protruding onto adjacent screens clipped. So if you can restrict use to 10.9 this may save you some work.
Borderless Windows: You can create a borderless non-opaque NSWindow, just set the appropriate flags. This is how applications create non-square windows, the visible area of the window is now entirely up to you. Now just clip your drawing to the area on one screen using the standard clipping support. You won't have a standard title bar or controls, unless you emulate them yourself, so you have to implement drag yourself etc. You say you have "some kind of a specially behaving mini window, not a usual one" so that may not be an issue.
Not that I've heard of.
What you could do though is restricting the position of the window e.g. via a NSWindowDelegate and windowDidMove: to listen to position changes and reposition the window appropriately.
Looking at a Windows tooltips class hint window, i see that it draws its drop-shadow outside the hint window's actual rectangle.
Using SpyXX - i can get the tooltip's window rect, and class styles:
Rectangle: (440, 229)-(544, 249), 104x20
Restored Rect: (440, 229)-(544, 249), 104x20
Client Rect: (0, 0)-(104, 20), 104x20
You'll notice that the drop shadow you see is physically outside the window that's being drawn. How can i draw a shadow outside around my window, while being outside my window?
Note: The shadow is not drawn using the standard CS_DROPSHADOW class style. i've confirmed this experimentally, and can also see the class style's for the window in SpyXX; it does not use CS_DROPSHADOW:
Windows Styles: 94000001
WS_POPUP 80000000
WS_VISIBLE 10000000
WS_CLIPSIBLINGS 4000000
TTS_ALWAYSTIP 1
Extended Styles: 00080088
WS_EX_LAYERED 80000
WS_EX_TOOLWIN 80
WS_EX_TOPMOST 8
So how can i draw outside my window?
Note: Trying to draw on the desktop DC is out. From Greg Schechter's Redirecting GDI, DirectX, and WPF applications:
Drawing To and Reading From the Screen
-- Baaaad!
Lastly, since we're on the redirection
topic, one particularly dangerous
practice is writing to the screen,
either through the use of GetDC(NULL)
and writing to that, or attempting to
do XOR rubber-band lines, etc. There
are two big reasons that writing to
the screen is bad:
It's expensive... writing to the
screen itself isn't expensive, but it
is almost always accompanied by
reading from the screen because one
typically does read-modify-write
operations like XOR when writing to
the screen. Reading from the video
memory surface is very expensive,
requires synchronization with the DWM,
and stalls the entire GPU pipe, as
well as the DWM application pipe.
It's unpredictable... if you somehow
manage to get to the actual primary
and write to it, there can be no
predictability as to how long what you
wrote to the primary will remain on
screen. Since the UCE doesn't know
about it, it may get cleared in the
next frame refresh, or it may persist
for a very long time, depending on
what else needs to be updated on the
screen. (We really don't allow direct
writing to the primary anyhow, for
that very reason... if you try to
access the DirectDraw primary, for
instance, the DWM will turn off until
the accessing application exits)
You can't draw outside your window in the manner you describe.
If you right click your desktop then go to properties/appearance/effects and uncheck 'Show shadows under menus' ... you will no longer have the shadow.
Bottom line is that this is a product of the window manager not your program.
Q: How do you draw outside of one window? A: Draw inside another window!
First thing to note is that the tooltip class actually does use the CS_DROPSHADOW style - but note that this is a class style, not a window style, so you have to look at the Class tab in the Spy++ properties dialog to find it. You'll see that the tooltips_class32 windows does indeed have this - and a few others.
But that just leads to the next question - how does that work? Well, it seems that Windows implements this by creating a helper HWND to draw the shadow - presumably it's creating another popup window the same size and shape as the one it's shadowing, filling it with gray, placing it directly underneath the main window, and setting it as a WS_EX_LAYERED window so that the shadow can be transparent and fade out around the edges using alpha-blending. And there's nothing to stop you from using the same or similar techniques yourself if you want to add a different type of shadow effect to one of your own windows.
So, long story short: if you want to draw outside of your own window, create a helper transparent window in the general area that you want to draw on, and draw on that helper window instead.
--
Now, if you try to find one of these helper shadow windows in Spy++, you won't find much. Unlike the tooltip_class32 windows, which are long-lived and just hide/show themselves as needed, these shadow windows are a more elusive creature: they are only created for as long as needed, so you'd have to refresh Spy++ while there's a tooltip or popup menu or other window using the shadow present - and that's tricky, since most tooltips and menus will disappear as soon as you move the mouse to switch to Spy++. But it turns out that the tooltips on Spy++'s own toolbar will stick around: so start Spy++, hover over an item in the toolbar, and hit F5 to refresh the HWND tree while the tooltip and shadow are present. Now scroll down, and you should see the third and fourth visible HWNDs in the tree are the tooltip itself, and right after that, a SysShadow window. Unfortunately, since the tooltip and shadow have by now disappeared, if you attempt to get the properties dialog for that HWND, you'll get a get a blank property dialog with an 'Invalid Window' message. If you really want to poke around and see how that SysShadow works, what styles it itself uses and so on, you could create a target app with a long-lived popup that uses CS_DROPSHADOW that you can then explore in Spy++ at leisure.
(Finally, note that these shadows are a completely different thing than the shadows that you see when one app window is on top of another above another since Vista: this type of shadow is part of Aero Glass mode, and handled by the same Desktop Composition Manager that adds the glass titlebar effect, and it doesn't use or need helper windows to implement the shadows.)
I wouldn't be surprised if that shadow is intimately tied to the window manager itself; it is after all the window manager who decides what window gets to paint which parts of itself and when it can do it. I don't see it as rocket science to paint that shadow if control over all that is gained, which the window manager has.
Is there a simple way to create a selectable NSRect in Cocoa? In need a rectangle that can be selected and stays selected after a mouse click.
Thanks.
NSRect is just a struct with a position and size. It's not an object that can actually do anything or have any properties other than a width and height. It sounds like what you want is to create an NSView that can be selected. (Here's Apple's Guide on the subject.)
Though not as immediate as you would like, you may be interested in the management of tracking rectangles and tracking areas performed by NSView class.
This mechanism allows you to define specific areas of your custom view. Then, an event is generated whenever the cursor enters or leaves the area, or a mouse button is pressed in this area (-mouseEntered:, -mouseExited:, -mouseDown:, -mouseUp:, -mouseDragged:, ... of NSResponder class). This up to you to define what you want your application do in response to these events (set the rectangle as selected and display it accordingly).
For an example implementation of this, take a look at the Sketch example included with the Apple developer tools (look in /Developer/Examples/AppKit). Sketch allows the user to create new graphics (including rectangles, but also ovals, lines, and text), select them, move them around in the document, etc. In particular, you'll probably want to look at the SKTGraphic class, which represents a single graphic object in the document, and the SKTGraphicView class, which is an NSView subclass that perform the actual layout and drawing, handling mouse events for dragging views around, etc.
I have some NSViews that I'm putting in one of two layouts depending on the size of my window.
I'm adjusting the layout when the relevant superview receives the resizeSubviewsWithOldSize method.
This works, but I'd like to animate the change. So naturally I tried calling the animator proxy when I set the new frames, but the animation won't run while the user is still dragging. If I release the mouse before the animation is scheduled to be done I can see the tail end of the animation, but nothing until then. I tried making sure kCATransactionDisableActions was set to NO, but that didn't help.
Is it possible to start a new animation and actually have it run during the resize?
I don't think you can do this easily because CA's animations are run via a timer and the timer won't fire during the runloop modes that are active while the user is dragging.
If you can control the runloop as the user is dragging, play around with the runloop modes. That'll make it work. I don't think you can change it on the CA side.
This really isn't an answer, but I would advise against animating anything while dragging to resize a window. The screen is already animating (from the window moving) - further animations are likely going to be visually confusing and extraneous.
CoreAnimation effects are best used to move from one known state to another - for example, when a preference window is resizing to accompany a new pane's contents, and you know both the old and new sizes, or when you are fading an object in or out (or both). Doing animation while the window is resizing is going to be visually confusing and make it harder for the user to focus on getting the size of the window where they want it to be.