I'm working on a custom implementation of UISegmentedControl.
I'd like to create a component that able to receive config data and from which obtain a custom View similar to UISegmentedControl.
I started subclassing a UIView and i can create a custom UISegmentedControl with this code:
CustomSegment *segment = [[CustomSegment alloc]
initWithTitles:[NSArray arrayWithObjects:#"one",#"two",nil]];
[self.window addSubview:segment];
But now i'd like to improve my class and add some more customizable parameters to it.
For example i'd like add a custom separators, define the button fonts and so on... here my doubt:
Is it better to work on a UIView subClass or you suggest me to subclass a UIViewController, where i can manage View hierarchy in method like -(void)loadView and -(void)viewDidLoad ?
In a simple UIView subclass, when i launch the custom init method, i setup immediately subviews... while using a UIViewController i can call custom init and define how my subview is builded into -(void)loadView.
Don't use an UIViewController, just extend the UIView class like you did and keep extending its functionality.
Remember to save a pointer to each subview you add (i.e. buttons) in order to be able to access them later.
Define custom setters, for example, a custom setter for changing a button label title would be:
- (void) setButton1Title:(NSString*)str forState:(UIControlState)state{
//You can add some control here
if ([str length] > 20) return;
[_button1 setTitle:str forState:state]; //_button1 is my reference to the button
}
And so on. Don't provide direct access to your subviews, use methods instead.
Also, you can use "layoutSubviews" method to define how your views are going to be displayed in your custom view.
Hope it helps you.
Edit: In your case, I don't see why using lauoutSubviews method but I want to show you what I was trying to say.
Lets say that for example I need to create an UIView class to represent a "Contact" object in my application.
This is what I would do:
#interface ContactView : UIView{
UILabel* _nameLabel;
UILabel* _ageLabel;
Contact* _contact;
}
#property (retain) Contact* contact;
#end
#implementation ContactView
#synthetize contact = _contact;
-(id)initWithContact:(Contact*)c{
self = [super init];
if (self) {
_nameLabel = [[UILabel alloc] init];
_nameLabel.frame = CGRectZero;
[self addSubview:_nameLabel];
[_nameLabel release];
_ageLabel = [[UILabel alloc] init];
_ageLabel.frame = CGRectZero;
[self addSubview:_ageLabel];
[_ageLabel release];
self.contact = c;
}
}
- (void) layoutSubviews{
[super layoutSubviews];
_nameLabel.frame = CGRectMake(0.0f, 0.0f, 200.0f, 25.0f);
_ageLabel.frame = CGRectMake(0.0f, 25.0f, 200.0f, 25.0f);
if (self.contact){
_nameLabel.text = self.contact.name;
_ageLabel.text = self.contact.age;
}else{
_nameLabel.text = #"Unavailable";
_ageLabel.text = #"Unavailable";
}
}
- (void) setContact:(Contact*)c{
self.contact = c;
[self layoutSubviews];
}
#end
Check out how the "layoutSubiews" is used to set the correct frame and data to the labels.
Usually, I use it a lot when creating custom UITableViewCells where you have to reuse the view.
Let me know if I'm being confusing.
Related
I need to add a save extension selector with a text label next to it to my NSSavePanel. In the screenshot attached I try to demonstrate that I succeeded in adding an NSComboBox to my panel with the function setAccessoryView. However I have no idea how to create a custom NSView, which includes both an NSComboBox and an NSTextView or equivalent. I found no tutorials on the internet (or if I found one it was extremely outdated) showing how to create custom NSViews in objective-C in Cocoa on MacOS.
How can I create a custom NSView containing a combobox and a text label? Or how can I add two "stock" NSViews to the same NSSavePanel? Please be as detailed in your answer as possible, as I have very limited objective-c experience.
You asked how to create an NSView in Objective-C with an NSTextField and an NSComboBox as subviews.
Basically, you could define them in Interface Builder and programmatically set the resulting view in Objective-C as the accessoryView of the NSSavePanel. Alternatively, the custom NSView could be created entirely in Objective-C, which is probably the easier option here.
After instantiating an NSView, you can use addSubview: to add an NSTextField and an NSComboBox accordingly. Then you can use NSLayoutConstraints to set up Auto Layout, which takes care of sizing the accessoryView and arranging the subviews properly based on the width of the dialog.
If you create the views programmatically and use Auto Layout, you must explicitly set translatesAutoresizingMaskIntoConstraints to NO.
Should you want to set the allowedContentTypes, a textual mapping of the displayed extension to UTType via a NSDictionary might be useful.
If you set the delegate of the NSComboBox to self, then you will be informed about changes of the user selection in the NSComboBox via comboBoxSelectionDidChange:.
If the things discussed are implemented appropriately in code, it might look something like this for a self-contained example:
#import <UniformTypeIdentifiers/UniformTypeIdentifiers.h>
#import "ViewController.h"
#interface ViewController () <NSComboBoxDelegate>
#property (nonatomic, strong) NSSavePanel *savePanel;
#property (nonatomic, strong) NSDictionary<NSString *, UTType*> *typeMapping;
#end
#implementation ViewController
- (instancetype)initWithCoder:(NSCoder *)coder {
if (self = [super initWithCoder:coder]) {
_typeMapping = #{
#"jpeg": UTTypeJPEG,
#"png": UTTypePNG,
#"tiff": UTTypeTIFF
};
}
return self;
}
- (NSView *)accessoryView {
NSTextField *label = [NSTextField labelWithString:#"Filetypes:"];
label.textColor = NSColor.lightGrayColor;
label.font = [NSFont systemFontOfSize:NSFont.smallSystemFontSize];
label.alignment = NSTextAlignmentRight;
NSComboBox *comboBox = [NSComboBox new];
comboBox.editable = NO;
for (NSString *extension in self.typeMapping.allKeys) {
[comboBox addItemWithObjectValue:extension];
}
[comboBox setDelegate:self];
NSView *view = [NSView new];
[view addSubview:label];
[view addSubview:comboBox];
comboBox.translatesAutoresizingMaskIntoConstraints = NO;
label.translatesAutoresizingMaskIntoConstraints = NO;
[NSLayoutConstraint activateConstraints:#[
[label.bottomAnchor constraintEqualToAnchor:view.bottomAnchor constant:-12],
[label.widthAnchor constraintEqualToConstant:64.0],
[label.leadingAnchor constraintEqualToAnchor:view.leadingAnchor constant:0.0],
[comboBox.topAnchor constraintEqualToAnchor:view.topAnchor constant:8.0],
[comboBox.leadingAnchor constraintEqualToAnchor:label.trailingAnchor constant:8.0],
[comboBox.bottomAnchor constraintEqualToAnchor:view.bottomAnchor constant:-8.0],
[comboBox.trailingAnchor constraintEqualToAnchor:view.trailingAnchor constant:-20.0],
]];
return view;
}
- (void)comboBoxSelectionDidChange:(NSNotification *)notification {
NSComboBox *comboBox = notification.object;
NSString *selectedItem = comboBox.objectValueOfSelectedItem;
NSLog(#"### set allowedContentTypes to %# (%#)", selectedItem, self.typeMapping[selectedItem]);
[self.savePanel setAllowedContentTypes:#[ self.typeMapping[selectedItem] ]];
}
- (IBAction)onSave:(id)sender {
NSWindow *window = NSApplication.sharedApplication.windows.firstObject;
self.savePanel = [NSSavePanel new];
self.savePanel.accessoryView = [self accessoryView];
[self.savePanel beginSheetModalForWindow:window completionHandler:^(NSModalResponse result) {
if (result != NSModalResponseOK) {
return;
}
NSURL *fileURL = self.savePanel.URL;
NSLog(#"### selectedFile: %#", fileURL);
}];
}
- (void)setRepresentedObject:(id)representedObject {
[super setRepresentedObject:representedObject];
}
#end
Finally, a screenshot of the above demo code in action looks like this:
Press Cmd-N to add a new file to your project. Choose a View file to add a xib file that has a custom view.
Open the xib file and add the controls to the custom view. Press the Add button in the project window toolbar to access the user interface elements.
Use the NSNib class to load the xib file and get the custom view.
I am hoping to "automate" a click on the segmentController with the index of 0.
My tabBar-based app has multiple segmentControllers in a tab in the ViewDidAppear method, I would like to automatically have it "click" the first segmented controller.
if (segmentController.selectedSegmentIndex == 0) {
//stuff here
}
if (segmentController.selectedSegmentIndex == 1) {
//stuff here
}
Does anyone know how I might accomplish this? Thank you!
If you're creating it programmatically, you could lazy load it like this:
#interface ExampleViewController : UIViewController
#property (nonatomic, strong) UISegmentedControl *segmentedControl;
- (void)segmentedControlClicked:(UISegmentedControl *)segmentedControl;
#end
#implementation ExampleViewController
- (UISegmentedControl *)segmentedControl
{
if (!_segmentedControl)
{
NSArray *items = #[#"First", #"Second", #"Third"];
_segmentedControl = [[UISegmentedControl alloc] initWithItems:items];
[_segmentedControl addTarget:self
action:#selector(segmentedControlClicked:)
forControlEvents:UIControlEventValueChanged];
[_segmentedControl setSelectedSegmentIndex:0]; // Set Default selection
CGRect frame = _segmentedControl.frame;
frame.origin = CGPointMake(0.0f, 0.0f); // Move to wherever you need it
[self.view addSubview:_segmentedControl];
}
return _segmentedControl;
}
- (void)segmentedControlClicked:(UISegmentedControl *)segmentedControl
{
// Whatever your code is goes here...
}
#end
If you're wanting a method to be called also initially, you can call it within your viewDidLoad: method as such:
- (void)viewDidLoad
{
[self.segmentedControl setSelectedSegmentIndex:0]; // Set desired default index (optional if set in lazy load as shown above)
[self segmentedControlClicked:self.segmentedControl];
}
This would hence simulate a click on desired default index.
Be careful putting the above into viewDidAppear: (you could if you really wanted to) because anytime the view comes to the front, this method will be called (in example, if this view controller presents a modal view controller, once the modal is dismissed, this view controller's viewDidAppear: method will be called).
Cheers!
Set the selectedSegmentIndex property on your UISegmentedControl in your viewDidAppear (or viewDidLoad) method.
self.segmentedController.selectedSegemntIndex = 1;
UISegmentedControl Reference
I'm trying to do draw a fancy UIButton using Quartz. I've declared my own button class like this:
#interface MyButton : UIButton
#end
In the .m file I'm constructing the button:
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
// Initialization code
CALayer *buttonLayer = self.layer;
buttonLayer.masksToBounds = YES;
CALayer *customDrawn = [CALayer layer];
customDrawn.delegate = self;
customDrawn.masksToBounds = YES;
[buttonLayer insertSublayer:customDrawn atIndex:0];
[customDrawn setNeedsDisplay];
}
return self;
}
But this results in some kind of recursion and finally fails with a EXC_BAD_ACCESS.
I've implemented a method drawLayer: inContext:, but it still crashes. The only way I can avoid the crash is by removing the delegate-assignment, but then I can't do any of the custom drawing I want to implement.
How can I make this work?
As described in the question mentioned by Kurt Revis, a UIView (such as UIButton) can't be used as a delegate for a sublayer. (It is already the delegate for the "main" layer of the UIView and can't be used as a delegate for another layer.) The solution is to use another object as a delegate which can be a "private" class just used to implement the drawLayer: inContext: method.
I have an interface that has an NSTextField, NSButton, and an NSView. When I type something in the NSTextfield and press the button, I want the text to be drawn in the NSView. So far I have everything connected and working, except for the view.
How can I connect the text and the view so that every time I press the button, the text is drawn to the view?
How can I connect the text and the view so that every time I press the button, the text is drawn to the view?
Views do their own drawing.
You need to give the view the string to draw, and then set the view as needing display. You'll do these in the action method that you wire the button up to.
First, your custom view class needs to have a property for the value (string, in this case) that it's going to display. From your action method, which should generally be on a controller object, send the view object a setFoo: message (assuming you named the property foo). That takes care of job one: The view now has the value to display.
Job two is even easier: Send the view a setNeedsDisplay: message, with the value YES.
That's it. The action method is two lines.
Of course, since views draw themselves, you also need your custom view to actually draw, so you need to implement the drawRect: method in that class. It, too, will be short; all you need to do is tell the string to draw itself.
Bindings
http://developer.apple.com/mac/library/documentation/cocoa/Conceptual/CocoaBindings/Concepts/WhatAreBindings.html#//apple_ref/doc/uid/20002372-CJBEJBHH
For simplicity's sake I didn't mention this before, but the app also has a speech element to speak the string. This aspect of the program works fine, so just ignore any messages involving the SpeakAndDraw class (it's actually misnamed and only includes a speech method, nothing about drawing).
View.m
#import "View.h"
#implementation View
#synthesize stringToDraw;
- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self setAttributes];
stringToDraw = #"Hola";
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect {
NSRect bounds = [self bounds];
[self drawStringInRect:bounds];
}
- (void)setAttributes
{
attributes = [[NSMutableDictionary alloc] init];
[attributes setObject:[NSFont fontWithName:#"Helvetica"
size:75]
forKey:NSFontAttributeName];
[attributes setObject:[NSColor blackColor]
forKey:NSForegroundColorAttributeName];
}
- (void)drawStringInRect:(NSRect)rect
{
NSSize strSize = [stringToDraw sizeWithAttributes:attributes];
NSPoint strOrigin;
strOrigin.x = rect.origin.x + (rect.size.width - strSize.width)/2;
strOrigin.y = rect.origin.y + (rect.size.height - strSize.height)/2;
[stringToDraw drawAtPoint:strOrigin withAttributes:attributes];
}
#end
SpeakerController.m
#import "SpeakerController.h"
#implementation SpeakerController
- (id)init
{
speakAndDraw = [[SpeakAndDraw alloc] init];
view = [[View alloc] init];
[mainWindow setContentView:mainContentView];
[mainContentView addSubview:view];
return self;
}
- (IBAction)speakText:(id)sender
{
[speakAndDraw setStringToSay:[text stringValue]];
[speakAndDraw speak];
[view setStringToDraw:[text stringValue]];
[view setNeedsDisplay:YES];
NSLog(#"%#", view.stringToDraw);
NSLog(#"%#", [view window]);
}
#end
I'm creating an instance of a viewController, and then trying to set the text on of it's properties, a UILabel.
BoyController *boyViewController = [[BoyController alloc] initWithNibName:#"BoyView" bundle:nil];
NSString *newText = [astrology getSignWithMonth:month withDay:day];
boyViewController.sign.text = newText;
NSLog(#" the boyviewcontroller.sign.text is now set to: %#", boyViewController.sign.text);
[newText release];
I tried this, but it didn't work...
So I tried the following:
BoyController *boyViewController = [[BoyController alloc] initWithNibName:#"BoyView" bundle:nil];
UILabel *newUILabel = [[UILabel alloc] init];
newUILabel.text = [astrology getSignWithMonth:month withDay:day];
boyViewController.sign = newUILabel;
NSLog(#" the boyviewcontroller.sign.text is now set to: %#", newUILabel.text);
[newUILabel release];
But no avail..
I'm not sure why I can't set the text property of the UILabel "sign" in boyViewController..
The problem here is that the initializer does not actually load the nib file into memory. Instead, loading the nib is delayed until your application requests the view controller's view property. As such, your controller's sign property is null when you access it.
Manually requesting the controller's view property would make your example work...
BoyController *boyViewController = [[BoyController alloc] initWithNibName:#"BoyView" bundle:nil];
[boyViewController view]; // !!!: Calling [... view] here forces the nib to load.
NSString *newText = [astrology getSignWithMonth:month withDay:day];
boyViewController.sign.text = newText;
// and so on...
However, I'd guess that what you're really trying to do is create and configure your view controller before setting it free to do it's own thing. (Perhaps to display it modally, say.) Calling [... view] manually is not going to be a long-term solution.
Better is to set a separate property on your view controller for the label text and then implement viewDidLoad to assign it to the label:
#interface BoyViewController : UIViewController {
IBOutlet UILabel *label;
NSString *labelText;
}
#property(nonatomic, copy)NSString *labelText;
#end
#implementation
#synthesize labelText;
- (void)viewDidLoad
{
[label setText:[self labelText]];
}
// and so on...
#end
This has the added benefit of your label text being reset in case the view is purged during a low memory event.
Did you bind your outlets at Interface Builder?
It seems that you need to bind sign outlet of the first example into Interface Builder in order to actually set that text to whatever you want.
Once you bind your outlet to the actual UI component at Interface Builder, then you should be able to do something like:
NSString *newText = [astrology getSignWithMonth:month withDay:day];
[[boyViewController sign] setText:newText];
This is what you need to know about binding.
Your second example does not make sense at all to me.