I’ve created a Cocoa-made text editing application that mimicks TextEdit with some
other features added. I use a subclass of NSTextView. My problem is, I can’t drag images (jpeg for example), into my text window, as I would do in TextEdit.
I tried the following : The -init method of my subclass is as follows :
- (id)init
{
self = [super init];
if (self) {
// Add your subclass-specific initialization here.
// If an error occurs here, send a [self release] message and return nil.
[self setImportsGraphics:YES];
}
return self;
}
But the problem stays the same ... Any help appreciated.
Are you sure that that init function is being called?
Perhaps you should override and add the "setImportGraphics" line to the initWithFrame:(NSRect)frame function instead.
Related
I have a subclassof NSWindowController with an associated xib file.
From my app delegate I display this using the following code:
if(!wc)
wc = [[NSWindowController alloc]initWithWindowNibName:#"MyNewWindowController"];
[wc showWindow:nil];
This displays the window. Now I want to reference that window in the new window controller but can't work out how. Specifically I have a button on the new window and I want to write something like:
- (IBAction)doStuffAndCloseWindow:(id)sender
{
[self doSomeStuff];
[*window* orderOut:nil];
}
I've tried creating a window variable (like the one created in appdelegate) but the compiler says my window variable is private.
So have do I declare and reference a window in my MyNewWindowController.m?
Thanks
That would be the 'window' method of NSWindowController. It's also a property that you can access via ".window".
So, in the first code snippet, that would be:
[wc window]
and in the second code snippet (assuming "doStuffAndCloseWindow" is part of your subclassed NSWindowController):
- (IBAction)doStuffAndCloseWindow:(id)sender
{
[self doSomeStuff];
[[self window] orderOut:nil];
}
Thanks to Michael, see above, first declare your subclassed NSwindowController thus
#property IBOutlet MyNewWindowController *wc;
Then in the implementation of the subclassed window controller, you can refer to the associated window with
[[self window] .....];
For example
[[self window] orderOut:self];
I have defined a custom class with a drawRect called Drawing. I have laid out the view in my NIB to contain an NSScrollView with a Drawing subview. When I launch the program, the screen is blank. Interestingly, when I create the documentView for the NSScrollView programmatically, I get an image in my scroll view. When I use the instance for the nib in my setDocumentView, I get nothing.
So if the Drawing view is set in IB,
[_scrollViewWorkspace setDocumentView:_drawing]; //does not work.
But
[_scrollViewWorkspace setDocumentView:[[Drawing alloc] initWithFrame:NSMakeRect(0,0,[[_scrollViewWorkspace documentView ]bounds].size.width, [[_scrollViewWorkspace documentView] bounds ].size.height)]];
Works great!
Why can't I statically bind a drawing object in a NIB?
When you set the custom class of the NSView subclass in the nib file to your custom class, at runtime, an instance of that class will be created using initWithCoder: rather than initWithFrame:.
You can easily check to see if this is the case by adding the following method to your custom Drawing view:
- (id)initWithCoder:(NSCoder *)coder {
NSLog(#"[%# %#]", NSStringFromClass([self class]), NSStringFromSelector(_cmd));
return [super initWithCoder:coder];
}
Then launch your app and see if [Drawing initWithCoder:] is logged to the console.
If you have overridden initWithFrame: in your Drawing class to do custom initialization (like set a custom image automatically), you will need to add that same code to the initWithCoder: method so that you end up with the same result:
- (id)initWithCoder:(NSCoder *)coder {
if ((self = [super initWithCoder:coder])) {
// do custom initialization here
}
return self;
}
Solved!
When I laid the view out in Interface Builder I just dragged the custom view to the NSScrollView in the canvas. I re-did the layout so that I used Embed->Scroll View and it worked.
Bruce
I'm new to Xcode and objective c. I want to create a button (probably a UIBarButtonItem, for a navigation bar) with a particular appearance, which I will use repeatedly in different views. I've searched at length but can't figure out how.
Would it be appropriate to subclass UIBarButtonItem? I tried to do that, but I was quickly in over my head. Once I create the .h and .m files as a subclass of UIBarButtonItem, do I then have to instantiate a UIBarButtonItem? Do those files not automatically create a button object for me (imported from the parent class), which I can refer to as self? It seems like it would be weird to instantiate a button within its own subclass.
One thing I want to do is add the line,
button.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
but I'm at a loss as to how to create reusable button with that property.
Even if that is completely the wrong approach to creating a reusable custom button, I clearly need to improve my understanding of objects, so explanation of my misunderstandings would be much appreciated!
Please?
You can do this without subclassing - by making a category (a preferred way of doing things in Objective-C). With a category you can provide custom methods for an object without having to subclass it. You can't (easily) provide custom properties, but in your case this is not relevant.
Using a Category
This is how your category header file could look:
// UIButton+StyledButton.h
#import <UIKit/UIKit.h>
#interface UIButton (StyledButton)
- (void) styleButton;
#end
Then in the implementation file:
//
// UIButton+StyledButton.m
//
#import "UIButton+StyledButton.h"
#implementation UIButton (StyledButton)
- (void) styleButton {
//style your button properties here
self.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
}
('self' refers to the button object, which also acquires the custom methods you write in the category.)
To use it, #import "UIButton+StyledButton.h" then you can do this sort of thing...
on viewDidLoad {
[super viewDidLoad];
UIButton* myButton = [[UIButton alloc] initWithFrame:myFrame];
[myButton styleButton];
}
Using a Subclass
The subclassed equivalent would look something like this:
The header file...
// MyCustomButton.h
#import <UIKit/UIKit.h>
#interface MyCustomButton : UIButton
- (id)initWithCoder:(NSCoder *)coder;
- (id)initWithFrame:(CGRect)frame;
#end
The implementation file...
// MyCustomButton.m
#import "MyCustomButton.h"
#implementation MyCustomButton
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self styleButton];
}
return self;
}
- (id)initWithCoder:(NSCoder *)coder
{
self = [super initWithCoder:coder];
if (self) {
[self styleButton];
}
return self;
}
- (void) styleButton {
//style your button properties here
self.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
}
You provide two init methods - initWithFrame is the method to call when alloc/initing the object in code; initWithCoder is the init method called by the system if loading the object from a storyboard or xib.
To create one of your custom buttons in code, you alloc/init as you would any other object:
MyCustomButton* button = [[MyCustomButton alloc] initWithFrame:buttonFrame];
You wouldn't also alloc/init the superclass instance, this is done by the initWithFrame: method in the subclass when it calls [super initWithFrame:frame]. self refers to your custom subclass instance, but that includes all of the (public) properties and methods from it's superclass - unless you have implemented overrides in the subclass.
To use your subclassed button in a storyboard/xib, just drag out a regular button then set it's type to your custom button class in the Identity Inspector. The initWithCoder method is called automatically when the button is loaded from the storyboard/xib into a view.
update
From your comments, you seem to harbour a few confusions still, so here are some highly compressed de-obfuscating notes...
Keep away from subclassing UINavigationController unless you really know what you are doing. It's rarely necessary.
The buttons on a navController's interface are properties of it's contained viewControllers. Look up the navigationItem property of UIViewController (similarly - in the case of a UIToolbar - the View Controller has a toolbarItems property). This allows Navigation Controllers to be context-aware.
The 'viewDidLoad' in my example is assumed to be in a regular UIViewController. My example is also a category on the regular UIBUtton which has no formal relationship with UIBarButtonItem.
Try getting a UIButton category to work with a regular ViewController first before experimenting with UIBarButtonItem (which does not inherit from UIButton).
UIBarbuttonItem has no initWithFrame, because the thing that organises the bar (UINavigationBar or UIToolbar) - in this case a Navigation Controller - is responsible for it's ultimate size and positioning. The viewController governs the relative order of barButtonItems, and whether they appear on the left or the right, and the content and (some aspects of) it's appearance, but the rest is up to the NavController.
I have an NSTableView that contains 2 different Columns - one is an NSImageCell that shows a file icon, and the second is a custom subclass of NSTextFieldCell that contains a quick look button on the right of the text. When I click the Quick Look button, the following code is invoked:
[[QLPreviewPanel sharedPreviewPanel] makeKeyAndOrderFront:nil];
This does it's job and shows the blank Quick Look panel saying "No Items Selected." After I did a bit of research on the internet, I implemented a custom NSTableView subclass to be the Delegate and Data Source for the Quick Look panel. I get the notification that Quick Look asks if I want to be the delegate, and I respond with return YES. Even though I implement all methods in both QLPreviewPanelDataSource and QLPreviewPanelDelegate, at runtime I get this error on the console:
2010-12-24 15:32:17.235 BackMeUp[4763:80f] clicked: ~/Desktop/HUDTape.mov
2010-12-24 15:32:17.489 BackMeUp[4763:80f] [QL] QLError(): -[QLPreviewPanel setDelegate:] called while the panel has no controller - Fix this or this will raise soon.
See comments in QLPreviewPanel.h for -acceptsPreviewPanelControl:/-beginPreviewPanelControl:/-endPreviewPanelControl:.
2010-12-24 15:32:17.490 BackMeUp[4763:80f] [QL] QLError(): -[QLPreviewPanel setDataSource:] called while the panel has no controller - Fix this or this will raise soon.
See comments in QLPreviewPanel.h for -acceptsPreviewPanelControl:/-beginPreviewPanelControl:/-endPreviewPanelControl:.
2010-12-24 15:32:17.491 BackMeUp[4763:80f] We can now receive QL Events.
2010-12-24 15:32:18.291 BackMeUp[4763:80f] -[NSPathStore2 stringValue]: unrecognized selector sent to instance 0x5ecb10
2010-12-24 15:32:18.292 BackMeUp[4763:80f] -[NSPathStore2 stringValue]: unrecognized selector sent to instance 0x5ecb10
And the Quick Look panel does not show up, which I find rather odd. The first line above is just that I know the cell has been clicked. Anyways, here is the .m file of the custom table view subclass:
//
// BackupListTableView.m
// BackMeUp
//
// Created by Tristan Seifert on 12/24/10.
// Copyright 2010 24/7 Server. All rights reserved.
//
#import "BackupListTableView.h"
#implementation BackupListTableView
- (void) awakeFromNib {
}
// Quick Look Delegates
- (BOOL)acceptsPreviewPanelControl:(QLPreviewPanel *)panel;
{
[QLPreviewPanel sharedPreviewPanel].delegate = self;
[QLPreviewPanel sharedPreviewPanel].dataSource = self;
NSLog(#"We can now receive QL Events.");
return YES;
}
- (void)beginPreviewPanelControl:(QLPreviewPanel *)panel
{
// This document is now responsible of the preview panel
// It is allowed to set the delegate, data source and refresh panel.
[QLPreviewPanel sharedPreviewPanel].delegate = self;
[QLPreviewPanel sharedPreviewPanel].dataSource = self;
}
- (void)endPreviewPanelControl:(QLPreviewPanel *)panel
{
// This document loses its responsisibility on the preview panel
// Until the next call to -beginPreviewPanelControl: it must not
// change the panel's delegate, data source or refresh it.
return;
}
// Quick Look panel data source
- (NSInteger)numberOfPreviewItemsInPreviewPanel:(QLPreviewPanel *)panel
{
return 1;
}
- (id <QLPreviewItem>)previewPanel:(QLPreviewPanel *)panel previewItemAtIndex:(NSInteger)index
{
int selectedRow = [self selectedRow];
return [NSURL URLWithString:[[[self dataSource] tableView:self objectValueForTableColumn:fileColumn row:selectedRow] stringValue]];
}
// Quick Look panel delegate
- (BOOL)previewPanel:(QLPreviewPanel *)panel handleEvent:(NSEvent *)event
{
// redirect all key down events to the table view
return NO;
}
// This delegate method provides the rect on screen from which the panel will zoom.
- (NSRect)previewPanel:(QLPreviewPanel *)panel sourceFrameOnScreenForPreviewItem:(id <QLPreviewItem>)item
{
NSRect iconRect = [self rectOfColumn:1];
/*
// check that the icon rect is visible on screen
NSRect visibleRect = [self visibleRect];
// convert icon rect to screen coordinates
iconRect = [self convertRectToBase:iconRect];
iconRect.origin = [[self window] convertBaseToScreen:iconRect.origin];
*/
return iconRect;
}
// This delegate method provides a transition image between the table view and the preview panel
- (id)previewPanel:(QLPreviewPanel *)panel transitionImageForPreviewItem:(id <QLPreviewItem>)item contentRect:(NSRect *)contentRect
{
int selectedRow = [self selectedRow];
NSImage *fileIcon = [[NSWorkspace sharedWorkspace] iconForFile:[[[self dataSource] tableView:self objectValueForTableColumn:fileColumn row:selectedRow] stringValue]];
return fileIcon;
}
#end
Thanks for any help.
The documentation isn't the best for this, since it's a new feature that was added in 10.6. (Well, there is obviously the class and protocol references, but in my experience, I've always found the Companion Guides to be more helpful in understanding how the objects are intended to be used in a real-world scenario).
The QLPreviewPanelController Protocol Reference defines 3 methods:
QLPreviewPanelController Protocol Reference
The Quick Look preview panel shows previews for items provided by the first object in the responder chain that implements the methods in this protocol. You typically implement these methods in your window controller or delegate. You should never try to modify preview panel state if you’re not controlling the panel.
- (BOOL)acceptsPreviewPanelControl:(QLPreviewPanel *)panel;
- (BOOL)beginPreviewPanelControl:(QLPreviewPanel *)panel;
- (void)endPreviewPanelControl:(QLPreviewPanel *)panel;
I'm guessing that your code should look like this:
- (BOOL)acceptsPreviewPanelControl:(QLPreviewPanel *)panel
{
return YES;
}
You shouldn't be doing anything in that method besides returning YES. acceptsPreviewPanelControl: is sent to every object in the responder chain until something returns YES. By returning YES, that object effectively becomes "the controller". The latter 2 methods are called on the controller object after it returns YES from the first method. So you should only be setting the delegate and datasource in the beginPreviewPanelControl: method (at which time you will be regarded as the current controller).
- (void)beginPreviewPanelControl:(QLPreviewPanel *)panel
{
// This document is now responsible of the preview panel
// It is allowed to set the delegate, data source and refresh panel.
[QLPreviewPanel sharedPreviewPanel].delegate = self;
[QLPreviewPanel sharedPreviewPanel].dataSource = self;
NSLog(#"We can now receive QL Events.");
}
First:
-acceptsPreviewPanelControl should only return YES and not try to set delegate and datasource.
Then, the problem is that you get an exception breaking the panel:
2010-12-24 15:32:18.291 BackMeUp[4763:80f] -[NSPathStore2 stringValue]: unrecognized selector sent to instance 0x5ecb10
The exception is very likely caused by these invocations:
[[[self dataSource] tableView:self objectValueForTableColumn:fileColumn row:selectedRow] stringValue]
Very likely, [[self dataSource] tableView:self objectValueForTableColumn:fileColumn row:selectedRow] is a file path (a NSPathStore instance which is a subclass of NSString) so it does not respond to -stringValue
So replace:
[NSURL URLWithString:[[[self dataSource] tableView:self objectValueForTableColumn:fileColumn row:selectedRow] stringValue]]
by:
[NSURL fileURLWithPath:[[self dataSource] tableView:self objectValueForTableColumn:fileColumn row:selectedRow]]
Also remove the call to -stringValue in transitionImageForPreviewItem.
As a side note, it seems to be suboptimal to load the image at each call of transitionImageForPreviewItem. I suppose you already have the image computed elsewhere (displayed in your table view), try to use it.
I am developing an plugin for OsiriX.
In that app i have 3-4 nib files. Also in for plugin there are files (.h & .m) called PluginFilter where method called - (long) filterImage:(NSString) menuName is present from which the plugin start execution. Now my problem is that, I have return the code to launch main window is in some other .m file and I have to call that file using the method mentioned above.
The app has multiple nib files. I have a plugin name PluginFilter called by:
- (long) filterImage:(NSString*) menuName
The plugin should open a window when called by this method. The code that defines the window controller is in another nib. When I call the filterimage method in the plugin, the window never appears.
Here is my filterImage: method.
#import "XGridInOsiriXFilter.h"
#import "MainWindowController.h"
#implementation XGridInOsiriXFilter
- (void) initPlugin
{
}
- (long) filterImage:(NSString*) menuName
{
MainWindowController *mainWindowController = [[GridSampleMainWindowController alloc] init];
[mainWindowController showWindow:self ];
[mainWindowController release];
return 0;
}
#end
Calling the method produces not warnings or errors, the window simply fails to appear.
I recognize this may be coming a little too late but I was looking for a way to do the same thing you are asking for and found it. You can use NSBundle to load the desired nib and point it to an instantiated controller. Like:
#implementation YourPluginFilter
- (void) initPlugin
{
yourWindowController = [[YourWindowController alloc] init];
NSLog(#"Initialized YourWindowController");
}
- (long) filterImage:(NSString*) menuName
{
if (yourWindowController && [NSBundle loadNibNamed:#"YourNibName" owner:yourWindowController]) {
NSLog(#"Activated yourWindowController");
return 0;
} else {
return -1;
}
}
#end
You would normally not open the app's main window from a plugin. Plugins by definition my not always be present so you should not put critical code in them. Neither would you want multiple plugins opening the same logical window.
Instead, the main window should be displayed by the app delegate as normal but the content of the window can be processed by a plugin if the plugin is available.
The main application should load and configure the main window and only call the plugin to process the contents of the window.
Even so it is technically possible to open a window from a plugin so either (1) the plugin is not being loaded and the method is not being called (insert breakpoint/log to confirm) or (2) the window controller is misconfigured so that it does not open the window. Test the controller outside the plugin to confirm it works. Better yet, move the window opening code outside the plugin.
Edit01:
From comment:
I have made some changes in the above
code as follows
- (long) filterImage:(NSString*) menuName {
MainWindowController *mainWindowController = [[GridSampleMainWindowController alloc] init:self];
[mainWindowController showWindow:self ];
[mainWindowController release];
return 0;
}
but it is showing wanring that no
-init method found. Why it is showing like this because -init method is der
in the MainWindowController.m file
Well, you have two problems here.
(1) You set define mainWindowController as of class MainWindowController but you initialize it with class GridSampleMainWindowController. If MainWindowController is a subclass of GridSampleMainWindowController this will work but will generate warnings. You should instead initialize it like
GridSampleMainWindowController *mainWindowController = [[GridSampleMainWindowController alloc] init:self];
or
MainWindowController *mainWindowController = [[MainWindowController alloc] init:self];
(2) You release the controller without any other object retaining it which will kill it. When a window controller dies it deallocates the windows it controls. This is most likely why you see nothing.
You should sort out what class you want the controller to be and then set it as a retained property of the plugin class so you can keep it an its window around.
Which init method is it complaining about? Your initPlugin does nothing and returns a void if that is the plugin's actual initialization method then the plugin will never load. It should at least look like this:
- (id) initPlugin
{
self=[super init];
return self;
}
It looks like you come from a pure C background which is great for this environment but you need to learn about the object oriented parts of the Objective-C language. You're still writing methods as if they were old school C functions and there are important and oft times subtle differences.
Sorry I missed all this yesterday. I saw "plugin" and focused on the wrong aspect of the problem.
Edit02:
No i m not talking about my initPlugin
method. I am talking about my init
method which is there in
MainWindowController.m file
- (id)init {
self = [super initWithWindowNibName:#"MainWindow"];
return self;
}
This will return an instance of the MainWindowController's super class. If you're not doing any customization you have no need to override the init method in you subclass. Just use the inherited version thusly:
MainWindowController *mainWindowController = [[MainWindowController alloc] initWithWindowNibName:#"MainWindow"];