so here is the deal:
I have a label (NSTextField) that I want to activate after I click a button. This label will appear while the program is loading some wavs (since it usually makes a minor delay when it does). I then want it gone once this has happened (and the new View appears).
Now, the problem I have is that this update does not seem to happen when I tried this. If I don't make it disappear at the end then I can see it, but only after the delay has occured (rendering it pointless).
Currently I am using:
[label2 setHidden:NO];
I understand that this will occur once the method I called it in has finished (which is a problem). Any idea what I could do instead so that the label is shown while the program is loading wavs?
Thanks heaps!!
Ok, I guess I solved it myself - I hope this helps people.
So when I click the button I disable the buttons and replace the label temporarily. This, however, only happens in the next view (so I'm not sure how to make it occur in the same view).
I disable the buttons for about 1 second, and it is here that the label is shown.
Here's some code to show what I mean:
- (IBAction)clickedTheButton:(id)sender {
[button setEnabled:NO];
[label2 setHidden:NO];
...
//Changes the View
[self nextMethod];
}
The View has now changed, and this method is called next. This enables me to see the label.
-(void)nextMethod{
...
[self performSelector:#selector(delayedDisplay:)
withObject:#"Hi"
afterDelay:1.0]; //delay for 1 second
}
This method then puts them back to their original state (so the label is hidden and the button is activated again)
-(void) delayedDisplay:(NSString *)string{
[button setEnabled:YES];
[label2 setHidden:YES];
}
Related
Strange things are happening here. Im working on a project which has a tableviewcontroller. The headersview are from a custom class which add a progressview and a button. When the button is clicked the progressview shows the download status en removes itself from the screen when done. Here is the problem.
The progressview isn't showing nor is it showing its progress (blue color). When I set the backgroundcolor to black I do see a black bar with no progress. Even when I set the progress to a static 0.5f.
Im also working with revealapp which shows the progressviews frame but not the trackingbar.
So the progressview is physically there but just not visible. Does anybody know why?
Structure:
Header.m
init:
[[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleDefault]
layoutSubviews:
CGRectMake(x, x, x, x);
Then:
- (void)synchMedia
{
// add progressview to view
[self performSelectorInBackground:#selector(synchMediaThread) withObject:nil];
}
- (void)synchMediaThread
{
// Do all the heavy lifting
// set progressview progress
// loop this:
[self performSelectorOnMainThread:#selector(updateProgressView:) withObject:progress waitUntilDone:YES];
// finally
[self performSelectorOnMainThread:#selector(synchDone:) withObject:#(numFailed) waitUntilDone:YES];
}
When done:
- (void)synchDone {
// remove progressview
[tableview reloadData];
}
Have you downloading any large data? If so then in that case updation on UI get blocked as main thread get busy.
To check this just add NSLog statement in a function which is calculating the progress of downloading. in this case it will log the progress on console but not on UI. If you get the correct progress on console then it is sure that UI updation is blocking when you start downloading.
Try to use some delay to update the UI or
dispatch_async(dispatch_get_main_queue(), ^{
//do you code for UI updation
});
The problem was with the way the UIView was used in the tableview delegate.
I have a UITableView which is populated with some cells. I have created a UIButton using the following snippet, it is placed next to one of the section headers.
UIButton *addButton = [UIButton buttonWithType:UIButtonTypeCustom];
[addButton addTarget:self action:#selector(addButtonPressed) forControlEvents:UIControlEventTouchUpInside];
[addButton setBackgroundImage:[UIImage imageNamed:#"add.png"] forState:UIControlStateNormal];
addButton.backgroundColor = [UIColor clearColor];
addButton.frame = CGRectMake(270, 150, 29, 29);
The button is placed and works correctly. However, after the view is scrolled (even slightly - like 1 pixel), the button works once and then ceases to respond. When it fails to respond the action for when it is clicked is not triggered and the button doesn't give the 'depressed' shadow. The rest of the application runs as normal and it does not crash.
This seems odd because after I scroll the button is clickable once more before it stops working. The button is used to insert rows into the table, so after it is pressed there is an extra row, possibly this is breaking the bounds or something?
Button pressed function:
- (void)addButtonPressed {
self.addClientTable.editing = YES;
// First figure out how many sections there are
NSInteger lastSectionIndex = [self numberOfSectionsInTableView:self.addClientTable] - 1;
// Then grab the number of rows in the last section
NSInteger lastRowIndex = [self.addClientTable numberOfRowsInSection:lastSectionIndex];
[self.addClientTable insertRowsAtIndexPaths:[NSArray arrayWithObject:[NSIndexPath indexPathForRow:lastRowIndex inSection:lastSectionIndex]] withRowAnimation:UITableViewRowAnimationRight];
self.addClientTable.editing = NO;
}
Where addClientTable is the UITableView.
What could cause a UIButton to stop responding to clicks and where in my scenario would this be caused by?
I am almost sure that your problem is that your button is out of it superview, and you are not using the clip subviews option in your view that contains the button, or in one of it superviews.
Set to true all the views property clip subviews and see if it appears your button. (We expect that the button disappear)
If you provide more code I can try to help you to solve this problem.
-
Reading again your question, another probable problem to it is that you have one view in front of your button. You can test it changing the background of your view, or something like that.
I'm trying to set up an image gallery type view where the image is nearly full screen, and the nav controller, toolbar, buttons (to move between images), and slider (to quickly move between images) all fade out after periods without interaction, and then return on a tap. What I have so far (which I'm sure isn't even close to the right way to do this, I'm something of a beginner) is this:
-(void)fadeOutViews{
[self fadeOutView:rightButton];
[self fadeOutView:leftButton];
[self fadeOutView:mySlider];
mySlider.enabled = NO;
[self fadeOutView:myToolbar];
[self fadeOutView:self.navigationController.navigationBar];
}
-(void)fadeOutView:(UIView *)view{
view.alpha = 1;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
[UIView setAnimationDelegate:self];
[UIView setAnimationDuration:2];
view.alpha = 0;
[UIView commitAnimations];
}
-(void)stopFadeOut{
[rightButton.layer removeAllAnimations];
[leftButton.layer removeAllAnimations];
[mySlider.layer removeAllAnimations];
[myToolbar.layer removeAllAnimations];
[self.navigationController.navigationBar.layer removeAllAnimations];
}
-(void)resetToInitialConfigurationWithDelay:(int)delay{
if (buttonWasPressed){
delay = 4;
buttonWasPressed = NO;
}
rightButton.alpha = 1;
leftButton.alpha = 1;
mySlider.alpha = 1;
myToolbar.alpha = 1;
self.navigationController.navigationBar.alpha = 1;
mySlider.enabled = YES;
[self stopFadeOut];
[self performSelector:#selector(fadeOutViews) withObject:nil afterDelay:delay];
}
So, the theory is, you reset to the initial state (the delay is because images fade in and out when using the buttons to advance, so there needs to be more time in before fading after a button press, or else the fading started immediately after the new image loaded. This resets everything to how it started out, and begins the process of fading again. And stopFadeOut removes all the animations if something occurs that should stop the fading process. So, for example, if a tap occurs:
- (IBAction)tapOccurs:(id)sender {
[self stopFadeOut];
[self resetToInitialConfigurationWithDelay:2];
}
Any previous animations are stopped, and then the process is restarted. Or at least that's the theory. In practice, if, say, there are several taps in quick succession, the faded views will start to fade briefly, and the reset, over and over again, so that it looks like they are flashing, until they finally fade out completely. I thought that perhaps the issue was the the animations were delayed, but the removeAllAnimation calls were not, so I replaced
[self stopFadeOut];
with
[self performSelector:#selector(stopFadeOut) withObject:nil afterDelay:2];
but the results were the same. The behavior is EXACTLY the same if stopFadeOut is never called, so the only conclusion I can draw is that for whatever reason, the removeAllAnimations calls aren't working. Any ideas?
What is happening
It sounds to me like the reset method is called multiple times before the previous run finished. You could easily verify this by adding log-statements to both the tap and reset method and count the number of logs for each method and watch what happens when you tap multiple times in a row.
I've tried to illustrate the problem with drawing below.
T = tapOccurs:
O = fadeOutViews:
--- = wait between T & O
Normal single tap
T-----O T-----O
---------------------> time
Multiple taps in a row
T-----O
T-----O
T-----O
---------------------> time
What it sound like you are trying to do
T-
T---
T-----O
---------------------> time
Every time fadeOutViews: (called O in the illustration) gets called the view will fade out. Looking at your fadeOutView: implementation this means that the opacity will jump to 1 and then fade slowly to 0, thus it looks like they are flashing an equal number of times to the number of taps until finally starting over.
How you can prevent this
You could do a number of things to stop this from happening. One thing would be to cancel all the scheduled reset methods by calling something like cancelPerformSelectorsWithTarget: or cancelPreviousPerformRequestsWithTarget:selector:object:.
I have programmed a Quiz in Xcode where I've created UIButtons programmatically displaying the answer to a question. When the user clicks the button the next question is loaded and the buttons position i shuffled to not make the right answer in the same place for each question (the right answer is however under the same UIButton for every question.)
This is how I create my buttons:
if (self.buttonRightAnswer == nil)
{
self.buttonRightAnswer = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[self.buttonRightAnswer addTarget:self action:#selector(rightAnswer) forControlEvents:UIControlEventTouchDown];
[self.view addSubview:self.buttonRightAnswer];
}
self.buttonRightAnswer.frame = CGRectMake(20.0, [[randomPositionArray objectAtIndex:0] floatValue], 280.0, 40.0);
[self.buttonRightAnswer setTitle:[[self.quiz.arrayWithQuestions objectAtIndex:questionNr - 1]valueForKey:#"RightAnswer"] forState:UIControlStateNormal];
When the user clicks the right an answer the next question loads. Here it's a problem. The next question loads with the same method only shuffled positions and the animation of the press-down of the button is drawn after the buttons been moved resulting in the user seeing where the right answer is now.
How can I wait for the animation before moving the buttons?
I could solve this by having the buttons stay in one place, shuffling out the questions over the buttons and comparing the users answer with the right answer.. but this requires a hell of a lot more code.
You can use some of shit-code and insert some kind of 'sleep' before next shuffling buttons
Before you create the buttons againg (after a question was answered), you can add something like (if you use differen images for button states)
-(void)waitUntilButtonDeselected
{
bool selected = YES;
while (selected)
{
bool selected = (self.buttonRightAnswer.currentBackgroundImage == UIImageOfNotSelectedButton);
}
}
The idea here is to check if the image of the button corresponds to not selected button.
Typically when using a UIButton, events are triggered on UIControlEventTouchUpInside, or at the end of the touch.
You're triggering it on the touch down which is causing issues with the animation you want to happen.
It might be simpler for you to switch to using UIControlEventTouchUpInside instead of UIControlEventTouchDown since this should solve your problem and be more consistent with other iPhone apps.
I am trying to add a UIButton to the view of a MPMoviePlayerController along with the standard controls. The button appears over the video and works as expected receiving touch events, but I would like to have it fade in and out with the standard controls in response to user touches.
I know I could accomplish this by rolling my own custom player controls, but it seems silly since I am just trying to add one button.
EDIT
If you recursively traverse the view hierarchy of the MPMoviePlayerController's view eventually you will come to a view class called MPInlineVideoOverlay. You can add any additional controls easily to this view to achieve the auto fade in/out behavior.
There are a few gotchas though, it can sometimes take awhile (up to a second in my experience) after you have created the MPMoviePlayerController and added it to a view before it has initialized fully and created it's MPInlineVideoOverlay layer. Because of this I had to create an instance variable called controlView in the code below because sometimes it doesn't exist when this code runs. This is why I have the last bit of code where the function calls itself again in 0.1 seconds if it isn't found. I couldn't notice any delay in the button appearing on my interface despite this delay.
-(void)setupAdditionalControls {
//Call after you have initialized your MPMoviePlayerController (probably viewDidLoad)
controlView = nil;
[self recursiveViewTraversal:movie.view counter:0];
//check to see if we found it, if we didn't we need to do it again in 0.1 seconds
if(controlView) {
UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
[controlView addSubview:backButton];
} else {
[self performSelector:#selector(setupAdditionalControls) withObject:nil afterDelay:0.1];
}
}
-(void)recursiveViewTraversal:(UIView*)view counter:(int)counter {
NSLog(#"Depth %d - %#", counter, view); //For debug
if([view isKindOfClass:NSClassFromString(#"MPInlineVideoOverlay")]) {
//Add any additional controls you want to have fade with the standard controls here
controlView = view;
} else {
for(UIView *child in [view subviews]) {
[self recursiveViewTraversal:child counter:counter+1];
}
}
}
It isn't the best solution, but I am posting it in case someone else is trying to do the same thing. If Apple was to change the view structure or class names internal to the control overlay it would break. I am also assuming you aren't playing the video full screen (although you can play it fullscreen with embeded controls). I also had to disable the fullscreen button using the technique described here because the MPInlineVideoOverlay view gets removed and released when it is pressed: iPad MPMoviePlayerController - Disable Fullscreen
Calling setupAdditionalControls when you receive the fullscreen notifications described above will re-add your additional controls to the UI.
Would love a more elegant solution if anyone can suggest something other than this hackery I have come up with.
My solution to the same problem was:
Add the button as a child of the MPMoviePlayerController's view;
fade the button in and out using animation of its alpha property, with the proper durations;
handle the player controller's touchesBegan, and use that to toggle the button's visibility (using its alpha);
use a timer to determine when to hide the button again.
By trial-and-error, I determined that the durations that matched the (current) iOS ones are:
fade in: 0.1s
fade out: 0.2s
duration on screen: 5.0s (extend that each time the view is touched)
Of course this is still fragile; if the built-in delays change, mine will look wrong, but the code will still run.