Intercepting the mouse coordinates and modifying it - macos

I would like to create an app that intercepts the mouse coordinates and modify them.
I want to build an app that runs in the background and intercepts the mouse movement, filtering it, for all apps running on macOS.
Suppose the mouse is scrolling freely but if the user presses a global shortcut, like CMD ALT X, the vertical scrolling is filtered and just the horizontal scrolling passes to macOS.
First question: what should I use to do that? Just point me in the right direction if the topic is too extensive.
Second question: is that possible to do for a sandbox app?

Related

How to detect trackpad/magic mouse scrolling on godot?

I am using a macbook, and have noticed that when adding an input to my project's input map to detect the scroll wheel, then calling it with "Input.is_action_just_released(scroll_up)", it works with a regular mouse with a normal scroll wheel, but not with my magic mouse or the trackpad on my mac. The input is set to be for all devices, not just device 0.
What am I doing wrong? I cannot seem to find an answer to this anywhere.

Discard mouse events on NSWindow based on click position

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).

Draw NSWindow on one screen only

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.

Gtk/GtkD Detect release of mouse button on window resize?

I'm trying to improve a plotting library that I wrote with GtkD (the D bindings for Gtk). Scatter plots with a lot of points take a long time to resize. I want to rescale the image, allowing pixelation, while the user is dragging the window edge to resize, and only re-render it when the mouse button is released.
Is there an API to detect whether the user is still holding down the mouse button to drag the window edge when a window is being resized? If you are not familiar with GtkD, a response in terms of the C Gtk API would still be appreciated.
you can add a 500 millisecond timeout to the redraw (resetting the timer on each resize event) this allows a user to see a preview while dragging

How to create a topmost overlay which ignores mouse clicks, etc

I'd like to know how to setup a transparent overlay windown in Cocoa which can ignore mouse clicks (so that they pass through to whatever window is below). The user should not be able to interact with the window with their mouse.
Tell it to ignore mouse events.

Resources