I would like the change the alpha of a UIButton when there is an EventTouchDown on it. I'm was hoping there was a way to do it similar to the below code:
[self.myButton setImage:<#(UIImage *)#> forState:UIControlEventTouchDown];
Is there a way to do something like this with "setAlpha"?
Thanks you!!!
You could subclass your UIButton (not recommended, but since all you'd end up doing is overriding setHighlighted or setSelected it shouldn't be much of an issue here) and override the tapping methods to handle your alpha change.
// In your UIButton's subclass
- (void)setHighlighted:(BOOL)highlighted {
[super setHighlighted:highlighted];
if(self.highlighted) {
[self setAlpha:0.5];
}
else {
[self setAlpha:1.0];
}
}
If you need to do something on selected you could do the same as in here
Related
I have my NSButton layer backed because I wanted to use a custom image, but this seems like it's inhibiting the use of the setFont: method when I need to programmatically change the font, as when I comment out the code for wantsUpdateLayer: and updateLayer:, setFont: works, but when the layer methods are in the code, it does nothing.
#implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
self.fontChangeButton = [[CustomButton alloc]initWithFrame:NSMakeRect(82, 60, 190, 113)];
[self.window.contentView addSubview:self.fontChangeButton];
}
- (IBAction)changeFont:(id)sender {
[self.fontChangeButton fontChange];
}
#end
#implementation CustomButton
- (void)fontChange{
[self setFont:[NSFont fontWithName:#"Dosis Bold" size:40]];
}
//when these are commented out, setFont: works, but I need them in for the custom button images
- (BOOL)wantsUpdateLayer{
return YES;
}
- (void)updateLayer{
if (self.state == NSOnState) {
self.layer.contents = [NSImage imageNamed:#"buttonPressed.png"];
}else
self.layer.contents = [NSImage imageNamed:#"buttonUnpressed.png"];
}
This thread offers a workaround, but I'd much rather understand why this is happening and fix it: Can't Change NSButton Font
By overriding -wantsUpdateLayer to return YES you're bypassing calls to -drawRect:. This facility was introduced in 10.8 and exists for efficiency purposes.
There are two things I think should be clarified:
1 - You don't need to override -wantsUpdateLayer to be layer-backed. Just send -setWantsLayer:YES to your button to be layer-backed.
2 - In your example, creating a custom NSButtonCell class might be a better approach to what you're trying to do. Have a look at Apple's documentation on subclassing NSControl and this how to to get started.
I'm trying to get the frame of a UIBarButtonItem, which just inherits from UIBarItem/NSObject.
In iOS 5.0, 5.1, and 6.0, use the following method. This method can be easily modified for use with a UIToolBar as well.
- (UIControl *) findBarButtonItem:(UIBarButtonItem *)barButtonItem
{
UINavigationBar *toolbar = self.navigationController.navigationBar;
UIControl *button = nil;
for (UIView *subview in toolbar.subviews) {
if ([subview isKindOfClass:[UIControl class]]) {
for (id target in [(UIControl *)subview allTargets]) {
if (target == barButtonItem) {
button = (UIControl *)subview;
break;
}
}
if (button != nil) break;
}
}
return button;
}
Usage:
UIControl *barButton = [self findBarButtonItem:myBarButtonItem];
CGRect barButtonFrame = barButton.frame;
This way works best for me:
UIView *targetView = (UIView *)[yourBarButton performSelector:#selector(view)];
CGRect rect = targetView.frame;
I know you posted this question for the purpose of posting the answer you found. I thought I would add an alternate solution that doesn't have the risk of breaking in a future iOS update.
If you create your UIBarButtonItem using a custom view then you can access the customView property of the UIBarButtonItem. The frame of the customView will reflect its position in the toolbar or navbar.
Obviously this solution prevents you from using the standard system defined buttons. But you can easily replicate them with your own image.
Generally the custom view you would use would be a UIButton with an appropriate icon image. One trick is to ensure you enable the button's showsTouchWhenHighlighted property so you get the usual highlight effect.
Setup the UIButton with the same target/action you would use on the UIBarButtonItem.
Here's a way to do this without having to resort to undocumented behaviour or assumptions.
Instead of using a UIBarButtonSystemItem, use a UIBarButtonItem with a custom view. You can get the image from the UIBarButtonSystemItem using a technique like this one:
Use UIBarButtonItem icon in UIButton
I have the following code:
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
CGRect textFieldRect = [self.view.window convertRect:textField.bounds fromView:textField];
CGRect viewRect = [self.view.window convertRect:self.view.bounds fromView:self.view];
...
}
As you can see it passes in a UITextField. I also have this code duplicated in the same ViewController but passing in a UITextView.
I want to be able to refactor this into a single method which passes in either the UITextField or UITextView? How can I do this?
Also this code appears in other View Controllers, so ideally I'd like to place it in a helper class, very new to iOS so not sure where to go from here.
I've removed most of the code from the method for brevity, but what it does is it slides the UI controls into view when the iOS keyboard appears.
You can expect UIView, as it seems you don't use any special text properties from those views.
-(void)textFieldDidBeginEditing:(UIView *)textField
{
CGRect textFieldRect = [self.view.window convertRect:textField.bounds fromView:textField];
CGRect viewRect = [self.view.window convertRect:self.view.bounds fromView:self.view];
// ...
}
Call a helper methods, that expects a UIView, the common super class.
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
return [self textBeginEditing:textField];
}
-(void)textViewDidBeginEditing:(UITextView *)textView
{
return [self textBeginEditing:textView];
}
-(void)textBeginEditing:(UIView *)view
{
//and if you need to do something, where you need to now, if it is a textView or a field, use
if([view isKindOfClass:[UITextField class]]){
//…
} else if([view isKindOfClass:[UITextView class]]){
//…
}
}
I have a UISearchDisplayController and UISearchBar hooked up to my ViewController via Outlets from my nib.
I'd like to hide the cancel button so that the user never sees it. The problem is that the following code hides the button, but only after displaying it to the user for a millisecond (e.g., it flashes on the simulator and device and then disappears out of view).
- (void)searchDisplayControllerDidBeginSearch:(UISearchDisplayController *)controller
{
controller.searchBar.showsCancelButton = NO;
}
Is there a better way to hide it?
I managed to hide the "Cancel" button by subclassing UISearchBar and override this method:
-(void)layoutSubviews{
[super layoutSubviews];
[self setShowsCancelButton:NO animated:NO];
}
I had the same issue, but fixed it a different way.
For those who can't or don't want to subclass UISearchDisplayController, I fixed the issue by adding a listener on UIKeyboardWillShowNotification, and setting [self setShowsCancelButton:NO animated:NO] there.
In viewWillAppear::
// Add keyboard observer:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(keyboardWillAppear:)
name:UIKeyboardWillShowNotification
object:nil];
Then you create:
- (void)keyboardWillAppear:(NSNotification *)notification
{
[YOUR-SEARCHBAR-HERE setShowsCancelButton:NO animated:NO];
}
Don't forget to add,
[[NSNotificationCenter defaultCenter] removeObserver:self];
in viewWillDisappear:!
Hope this helps!
Similar to Nimrod's answer, you can also subclass UISearchDisplayController and implement the setActive:animated: method:
- (void)setActive:(BOOL)visible animated:(BOOL)animated {
[super setActive:visible animated:animated];
self.searchBar.showsCancelButton = NO;
}
This seems to be a bug within Xcode. I submitted this error to Apple's bug reporting site, and they've followed up asking for more sample code and use-cases.
Thanks everyone for your attempt at solving this problem.
class CustomSearchBar: UISearchBar {
override func setShowsCancelButton(showsCancelButton: Bool, animated: Bool) {
super.setShowsCancelButton(false, animated: false)
}
}
class CustomSearchController: UISearchController, UISearchBarDelegate {
lazy var _searchBar: CustomSearchBar = {
[unowned self] in
let customSearchBar = CustomSearchBar(frame: CGRectZero)
customSearchBar.delegate = self
return customSearchBar
}()
override var searchBar: UISearchBar {
get {
return _searchBar
}
}
}
Had this problem when using the UISearchBar with UISearchController. I'm using my own cancel button, as the cancel button wasn't showing on iPad with showsCancelButton = YES, now it won't hide on iPhone with showsCancelButton = NO!
The following worked for me.
Set the delegate, and initial value:
- (void)viewDidLoad
{
// ...
self.searchController.searchBar.showsCancelButton = NO;
self.searchController.searchBar.delegate = self;
}
Reset showsCancelButton to NO 0.1s after the text bar begins editing.
#pragma mark - UISearchBarDelegate
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
self.searchController.searchBar.showsCancelButton = NO;
});
}
If you want to avoid the subclassing, implement
searchController.searchBar.showsCancelButton = false;
in these two delegate methods (Do not forget to assign delegates):
- (void)updateSearchResultsForSearchController:(UISearchController *)searchController
- (void)didPresentSearchController:(UISearchController *)searchController
The first one is called everytime you update the searchBar (Cancel button is visible by default) and the second one is for the first searchBar activation.
Just based on issues I've had before have you tried setting it in:
- (void)searchDisplayControllerWillBeginSearch:(UISearchDisplayController *)controller
I don't know how to ask this question in your question sorry if this is out of place.
If the cancel button shows up when editing the search field of the search bar you could do the following; subclass the search bar and have it implement the UITextFieldDelegateprotocol:
#interface CustomAlignedSearchBar : UISearchBar<UITextFieldDelegate>
Then implement textFieldDidBeginEditing: and do something like:
- (void)textFieldDidBeginEditing:(UITextField *)textField{
[self setShowsCancelButton:self.cancelButtonShown animated:NO];
}
This will make sure that the cancel button will not show up.
After UISearchDisplayController deprecated in iOS8, Apple give handle search presentation to UISearchControllerDelegate.
so you can override searchBar to hide the Cancel button, like below :
- (void)didPresentSearchController:(UISearchController *)searchController {
[searchController.searchBar setShowsCancelButton:NO];
}
if you need hidden Cancel button from inactive state, you need set searchBar on init :
search = [[UISearchController alloc] initWithSearchResultsController:nil];
[search.searchBar setShowsCancelButton:NO];
On iOS 13.0 and later, UISearchController has this property you can use:
#property (nonatomic) BOOL automaticallyShowsCancelButton API_AVAILABLE(ios(13.0)); // Default YES
I have a working NSCollectionView with one minor, but critical, exception. Getting and highlighting the selected item within the collection.
I've had all this working prior to Snow Leopard, but something appears to have changed and I can't quite place my finger on it, so I took my NSCollectionView right back to a basic test and followed Apple's documentation for creating an NSCollectionView here:
http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/CollectionViews/Introduction/Introduction.html
The collection view works fine following the quick start guide. However, this guide doesn't discuss selection other than "There are such features as incorporating image views, setting objects as selectable or not selectable and changing colors if they are selected".
Using this as an example I went to the next step of binding the Array Controller to the NSCollectionView with the controller key selectionIndexes, thinking that this would bind any selection I make between the NSCollectionView and the array controller and thus firing off a KVO notification. I also set the NSCollectionView to be selectable in IB.
There appears to be no selection delegate for NSCollectionView and unlike most Cocoa UI views, there appears to be no default selected highlight.
So my problem really comes down to a related issue, but two distinct questions.
How do I capture a selection of an item?
How do I show a highlight of an item?
NSCollectionView's programming guides seem to be few and far between and most searches via Google appear to pull up pre-Snow Leopard implementations, or use the view in a separate XIB file.
For the latter (separate XIB file for the view), I don't see why this should be a pre-requisite otherwise I would have suspected that Apple would not have included the view in the same bundle as the collection view item.
I know this is going to be a "can't see the wood for the trees" issue - so I'm prepared for the "doh!" moment.
As usual, any and all help much appreciated.
Update 1
OK, so I figured finding the selected item(s), but have yet to figure the highlighting. For the interested on figuring the selected items (assuming you are following the Apple guide):
In the controller (in my test case the App Delegate) I added the following:
In awakeFromNib
[personArrayController addObserver:self
forKeyPath:#"selectionIndexes"
options:NSKeyValueObservingOptionNew
context:nil];
New Method
-(void)observeValueForKeyPath:(NSString *)keyPath
ofObject:(id)object
change:(NSDictionary *)change
context:(void *)context
{
if([keyPath isEqualTo:#"selectionIndexes"])
{
if([[personArrayController selectedObjects] count] > 0)
{
if ([[personArrayController selectedObjects] count] == 1)
{
personModel * pm = (PersonModel *)
[[personArrayController selectedObjects] objectAtIndex:0];
NSLog(#"Only 1 selected: %#", [pm name]);
}
else
{
// More than one selected - iterate if need be
}
}
}
Don't forget to dealloc for non-GC
-(void)dealloc
{
[personArrayController removeObserver:self
forKeyPath:#"selectionIndexes"];
[super dealloc];
}
Still searching for the highlight resolution...
Update 2
Took Macatomy's advice but still had an issue. Posting the relevant class methods to see where I've gone wrong.
MyView.h
#import <Cocoa/Cocoa.h>
#interface MyView : NSView {
BOOL selected;
}
#property (readwrite) BOOL selected;
#end
MyView.m
#import "MyView.h"
#implementation MyView
#synthesize selected;
-(id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
}
return self;
}
-(void)drawRect:(NSRect)dirtyRect
{
NSRect outerFrame = NSMakeRect(0, 0, 143, 104);
NSRect selectedFrame = NSInsetRect(outerFrame, 2, 2);
if (selected)
[[NSColor yellowColor] set];
else
[[NSColor redColor] set];
[NSBezierPath strokeRect:selectedFrame];
}
#end
MyCollectionViewItem.h
#import <Cocoa/Cocoa.h>
#class MyView;
#interface MyCollectionViewItem : NSCollectionViewItem {
}
#end
"MyCollectionViewItem.m*
#import "MyCollectionViewItem.h"
#import "MyView.h"
#implementation MyCollectionViewItem
-(void)setSelected:(BOOL)flag
{
[(MyView *)[self view] setSelected:flag];
[(MyView *)[self view] setNeedsDisplay:YES];
}
#end
If a different background color will suffice as a highlight, you could simply use an NSBox as the root item for you collection item view.
Fill the NSBox with the highlight color of your choice.
Set the NSBox to Custom so the fill will work.
Set the NSBox to transparent.
Bind the transparency attribute of the NSBox to the selected attribute of File Owner(Collection Item)
Set the value transformer for the transparent binding to NSNegateBoolean.
I tried to attach Interface builder screenshots but I was rejected bcos I'm a newbie :-(
Its not too hard to do. Make sure "Selection" is enabled for the NSCollectionView in Interface Builder. Then in the NSView subclass that you are using for your prototype view, declare a property called "selected" :
#property (readwrite) BOOL selected;
UPDATED CODE HERE: (added super call)
Subclass NSCollectionViewItem and override -setSelected:
- (void)setSelected:(BOOL)flag
{
[super setSelected:flag];
[(PrototypeView*)[self view] setSelected:flag];
[(PrototypeView*)[self view] setNeedsDisplay:YES];
}
Then you need to add code in your prototype view's drawRect: method to draw the highlight:
- (void)drawRect:(NSRect)dirtyRect
{
if (selected) {
[[NSColor blueColor] set];
NSRectFill([self bounds]);
}
}
That just simply fills the view in blue when its selected, but that can be customized to draw the highlight any way you want. I've used this in my own apps and it works great.
You can also go another way, if you're not subclassing NSView for your protoype view.
In your subclassed NSCollectionViewItem override setSelected:
- (void)setSelected:(BOOL)selected
{
[super setSelected:selected];
if (selected)
self.view.layer.backgroundColor = [NSColor redColor].CGColor;
else
self.view.layer.backgroundColor = [NSColor clearColor].CGColor;
}
And of course, as said by all the wise people before me, make sure "Selection" is enabled for the NSCollectionView in Interface Builder.
In your NSCollectionViewItem subclass, override isSelected and change background color of the layer. Test in macOS 10.14 and Swift 4.2
class Cell: NSCollectionViewItem {
override func loadView() {
self.view = NSView()
self.view.wantsLayer = true
}
override var isSelected: Bool {
didSet {
self.view.layer?.backgroundColor = isSelected ? NSColor.gray.cgColor : NSColor.clear.cgColor
}
}
}
Since none of the existing answers worked super well for me, here is my take on it. Change the subclass of the CollectionView item to SelectableCollectionViewItem. Here is it's code. Comes with a bindable textColor property for hooking your text label textColor binding to.
#implementation SelectableCollectionViewItem
+ (NSSet *)keyPathsForValuesAffectingTextColor
{
return [NSSet setWithObjects:#"selected", nil];
}
- (void)viewDidLoad {
[super viewDidLoad];
self.view.wantsLayer = YES;
}
- (void) viewDidAppear
{
// seems the inital selection state is not done by Apple in a KVO compliant manner, update background color manually
[self updateBackgroundColorForSelectionState:self.isSelected];
}
- (void)updateBackgroundColorForSelectionState:(BOOL)flag
{
if (flag)
{
self.view.layer.backgroundColor = [[NSColor alternateSelectedControlColor] CGColor];
}
else
{
self.view.layer.backgroundColor = [[NSColor clearColor] CGColor];
}
}
- (void)setSelected:(BOOL)flag
{
[super setSelected:flag];
[self updateBackgroundColorForSelectionState:flag];
}
- (NSColor*) textColor
{
return self.selected ? [NSColor whiteColor] : [NSColor textColor];
}
In my case I wanted an image(check mark) to indicate selection of object. Drag an ImageWell to the Collection Item nib. Set the desired image and mark it as hidden. Go to bindings inspector and bind hidden attribute to Collection View Item.
(In my case I had created a separate nib for CollectionViewItem, so its binded to File's owner. If this is not the case and Item view is in the same nib as the CollectionView then bind to Collection View Item)
Set model key path as selected and Value transformer to NSNegateBoolean. Thats it now whenever the individual cells/items are selected the image will be visible, hence indicating the selection.
Adding to Alter's answer.
To set NSBox as root item. Simply create a new IB document(say CollectionItem) and drag an NSBox to the empty area. Now add all the elements as required inside the box. Now click on File's Owner and set Custom Class as NSCollectionViewItem.
And in the nib where NSCollectionView is added change the nib name for CollectionViewItem
In the NSBox, bind the remaining elements to Files Owner. For a label it would be similar to :
Now to get the highlight color as Alter mentioned in his answer, set desired color combination in the Fill Color option, set the NSBox to transparent and bind the transparency attribute as below:
Now when Collection View Items are selected you should be able to see the fill color of the box.
This was awesome, thanks alot! i was struggling with this!
To clarify for to others:
[(PrototypeView*)[self view] setSelected:flag];
[(PrototypeView*)[self view] setNeedsDisplay:YES];
Replace PrototypeView* with the name of your prototype class name.
In case you are digging around for the updated Swift solution, see this response.
class MyViewItem: NSCollectionViewItem {
override var isSelected: Bool {
didSet {
self.view.layer?.backgroundColor = (isSelected ? NSColor.blue.cgColor : NSColor.clear.cgColor)
}
}
etc...
}
Here is the complete Swift NSCollectionViewItem with selection. Don't forget to set the NSCollectioView to selectable in IB or programmatically.
Tested under macOS Mojave (10.14) and High Sierra (10.13.6).
import Cocoa
class CollectionViewItem: NSCollectionViewItem {
private var selectionColor : CGColor {
let selectionColor : NSColor = (isSelected ? .alternateSelectedControlColor : .clear)
return selectionColor.cgColor
}
override var isSelected: Bool {
didSet {
super.isSelected = isSelected
updateSelection()
// Do other stuff if needed
}
}
override func viewDidLoad() {
super.viewDidLoad()
view.wantsLayer = true
updateSelection()
}
override func prepareForReuse() {
super.prepareForReuse()
updateSelection()
}
private func updateSelection() {
view.layer?.backgroundColor = self.selectionColor
}
}