I have NSButton created on interface builder for this app of mine.
When this button is pressed the app starts to render an image. At this time the button's label change to PRESS TO CANCEL RENDER.
The render happens on a second thread but because the app is busy, it may take one or two seconds for the render to stop when that button is clicked. At this time the user may get impatient and click repeatedly on the button, making the app stop, start, stop, start, etc., the render.
Even not responding to the action immediately, the app stores all clicks on that button and processes them when possible.
Is there a way to set the app in a way that when it starts rendering it will accept just one click on that button (to stop the render) and ignore all others until the render finally stops?
You can use
[_yourButtonOutlet setEnable:NO];
and then enable it when the rendering has stopped completely.
Related
I'm trying to implement system-wide drag operation with middle mouse button. It should override middle mouse drag behavior in other programs. Currently, I am handling global mouse events with system-wide hooks.
Problem is - many programs still receive and handle same events like I did not intercept them.
Here's what I tried:
not call the next hook for mouse down event: I never receive mouse up, so I don't know where and when to stop dragging
not call the next hook for mouse move: cursor slows down tremendously
not call the next hook for mouse up: most windows in the system stop reacting to mouse events completely after my drag is finished
always call the next hook in the chain: if the control under mouse has scroll in it, most of the time it will be scrolling while my drag is in progress. Also UWP apps continue receiving mouse events during my drag, so if a link in MS Edge happens to be under cursor when it started, and mouse does not leave Edge boundary, Edge receives click event, and new tab is opened
What I need is: when user holds middle mouse and starts dragging, my drag handler should be called, and no other handlers, like file drag, scroll, etc should happen.
I ended up with somewhat hacky solution:
do not call the next hook for mouse down for middle button
record where it was pressed
when handling mouse up, if user did not drag - replay the whole mouse up + mouse down using SendInput from a separate thread (to avoid deadlock due to reentrancy)
Most mouse-APIs allow one to check weather or not a mouse button was pressed or released. As an example: The Java-Swing-API also allows to check for a "click" event, that is just an additional event that get's triggered whenever a "release" event was triggered after a "press" event, though it is hard to imagine to a scenario where this does not happen.
When implementing my own UI with a common mouse API, I now wonder how to register a "click" upon a general button. I went ahead and checked various UIs used by various programs I use and I got the general feel that any button is considered "clicked" when the mouse button is released above it.
They do not require the mouse-button to be "pressed" above them before being "released". It seems the "pressed"-event only tries to catch an object to be "dragged", though most mouse-APIs have their own "dragged" event to be triggered, the "pressed" event seems to be used to select the item that should be dragged.
Then right as I write this, it seems that browsers do not allow button presses when the mouse was not "pressed" upon the button before being "released" above it.
Question 1: Do I miss something here or am I right in these observations?
As such, a "UI"-Class managing the components of any UI needs to consider:
It's components to be drawn
The components that are focused
The components that have been "pressed" and are as such "dragged"
A "click" is triggered simply when the mouse button is "released" upon all components that are "focused". Or a "click" is triggered upon all components that were "pressed" and are still "focused"?
Question 2/3: Will this implementation be a good start or do I miss something? Which one is better?
Question 1:
Pressed: event is generated when you push down the mouse button
Released: event is generated when you release the mouse button (which has been pressed down before)
Clicked: event is generated when a mouse button Pressed & Released.
I have 2 NSButtons, both are bordered momentary push-in buttons. I have a main window to which other views are swapped in and out. These two buttons are in the main window custom view (next,previous) which helps to navigate through the views.
When I reach the 2 view with the help of next button, I make the previous button enabled and visible. So if I press the previous button at this point the 1st view will be swapped in and I make the previous button transparent and enabled.
At this point if you press the next button to navigate to second view, the 2nd view will be swapped in and the previous button is displayed again. But it is highlighted here. How can I get rid of this?
I hope you will get some better answers, but a general technique that I have found to work in cases like this is to wait with enable/disable actions until things have settled down for the new configuration of the views.
After all (if I have read your description correctly), you are hiding a button in the middle of its own action handler.
Postponing this is easily obtained by dispatching your enable/disable code on the next (or, more correctly, a later) invocation of the run loop of the main thread:
dispatch_async(dispatch_get_main_queue(), ^{
// Enable or disable your buttons here.
});
As a solution it is somewhat of a hack, but on the other hand, waiting until your main view is no longer in a state of flux before you re-configure your navigation UI is not a bad approach.
Hi We are using Flex 4 in our project on UI side. On loading the application dashboard, we get a set of pods. We click on a pod and the pod view opens. This pod view contains datagrid with the first column as a hyperlink. When you click on hyperlink another screen opens which is our module screen.
This module screen has a SUBMIT button on top and a couple of datagrids. Now we load data in the grids using RemoteObject. The parent container for each of the grid is a WindowShade Component.
Now our requirement is that the user can make modifications in one or both of the grids and click SUBMIT. Depending upon which grid the user has modified I want to make the corresponding Window shade as read only. IF the user modifies both the grids, I need to make both the Window Shade components as read only and disable the SUBMIT button. The user should be able to see this change immediately on click of SUBMIT without closing the screen or navigating away from the screen.
When the user opens screen for the first time, we get some statuses from backend and Depending upon these statuses, I make the Window shades as read only and enable/disable the buttons. When I click SUBMIT, I still hit the backend and get the status but no enabling/disabling of buttons or window shade happens.
I have written the logic for enabling/disabling in the updateComplete method of my mxml file for which swf is created.
the updateComplete gets called when user opens screen for the first time.It does not get called when the user clicks SUBMIT. why is it so?
I have tried using Loader and SWFLoader to load my SWF file as below but it is not working either.
var request:URLRequest = new URLRequest("com/citi/risk/credit/maintenance/view/widgets/CRCMaintenanceModule.swf");
var loader:Loader = new Loader();
loader.load(request);
Any help or pointers would be greatly appreciated.
Two things you may want to consider:
1) In short, FlexEvent.UPDATE_COMPLETE is an event that gets dispatched has completed rendering itself (gone through a Flex component life cycle). This could happen once, or many times depending on how often the component changes and it's state needs to be re-rendered.
The frequency/timing of this event will vary based on the object that is dispatching it. For example a container that is being resized will dispatch this numerous time. A label that never changes may only do it once.
Instead, you should consider adding a "creationComplete" (FlexEvent.CREATION_COMPLETE) event listener. "creationComplete" only happens once, you can add the listener to any object that contains the submit button.
2) When you click submit, the object you've added the "updateComplete" listener to probably hasn't changed enough to go through Flex's component life cycle. So no event is dispatched.
The answer to why this doesn't happen actually depends on which object you have added the event listener to.
Have you tried using a "click" handler on the submit button, so you could disable the appropriate elements when the button is clicked? Again, the "click" event will happen only once, unlike "updateComplete" ;)
In almost any Windows application, I notice that holding the mouse button down in a non-client area causes the painting to stop. Why is this required?
For example, I have a Managed Direct 3D application which displays a spinning cube. If I place the pointer over the title bar and hold the mouse button down, the cube ceases to spin even though I have not coded any such condition into my loop.
Why is painting halted? What are the benefits? Most importantly, how can I work around this?
When you click on the title bar, there's a brief pause while the window manager tries to determine whether or not you're clicking or beginning a drag (moving the window). If you're still holding down the button, then it's a drag: the window manager sets up its own message loop and pumps messages until you release the mouse. Your window should still be able to process messages, because they'll still be dispatched, but if your animation depends on a custom message loop then you'll be stuck 'till the modal drag loop ends.
Work around it by triggering your animation in response to messages: a timer seems like a good choice to me.