i have created the NSViewController for managing the PXListView....delegate is connect with File owner...
here everything is working as per the expectation..except drag and drop...
while dragging it is not entering into the dragging delegate function...and it is not showing the + symbol while dragging(i.e dragging symbol)... and dragging cells relocates to its original position
#import "PXListView.h"
#interface ListViewController : NSViewController <PXListViewDelegate>
{
IBOutlet PXListView *listView;
NSMutableArray *_listItems;
int count;
}
- (void)addCell;
#end
- (BOOL)listView:(PXListView*)aListView writeCellsWithIndexes:(NSIndexSet*)rowIndexes toPasteboard:(NSPasteboard*)dragPasteboard
{
// +++ Actually drag the items, not just dummy data.
[dragPasteboard declareTypes: [NSArray arrayWithObjects: NSStringPboardType, nil] owner: self];
[dragPasteboard setString: #"Just Testing" forType: NSStringPboardType];
return YES;
}
- (NSDragOperation)listView:(PXListView*)aListView validateDrop:(id <NSDraggingInfo>)info proposedCell:(NSUInteger)row
proposedDropHighlight:(PXListViewDropHighlight)dropHighlight;
{
return NSDragOperationCopy;
}
- (BOOL)listView:(PXListView*)aListView acceptDrop:(id <NSDraggingInfo>)info row: (NSUInteger)row dropHighlight:(PXListViewDropHighlight)dropHighlight
{
NSLog(#"Accept Drop");
ListViewThumbnailObject *temp = [_listItems objectAtIndex: [listView selectedCell]];
[_listItems removeObjectAtIndex: [listView selectedCell]];
[_listItems insertObject: temp atIndex: row];
[listView reloadData];
return YES;
}
it is not entering into the drag related delegate methods..
in the "nib" file delegate is wired with file owner...
can anyone please suggest me how to solve this problem?
Thanks,
Muthu
To be able to accept drops, you will likely need to assure you register the list view for all dragged types you plan on accepting. Try adding this in the awakeFromNib method in your list view controller class:
- (void)awakeFromNib {
[listView registerForDraggedTypes:[NSArray
arrayWithObjects:NSStringPboardType, nil]];
}
See Drag and Drop Programming Topics: Receiving Drag Operations for more info.
Note that I used NSStringPboardType in the array here because that's the type you declared for writing in the listView:writeCellsWithIndexes:toPasteboard: method. The exact array of types you use will depend on the types you want to support, and the type of drag operations you want to support (for example, do you just want to implement drag and drop to allow reordering of items in a single list view, or do you want to allow dragging items from the Finder, or to the Finder, or between different views in your own application). If you describe the type of drag operations you hope to support I can provide more details on how you might want to implement them.
Related
I am trying to solve this issue regarding a UITableView cell being off screen, or outside the visible area.
Within my tableview cells I have a UITextField which I am able to parse easily using the code below. However I find that that for the cells that are not visible it returns a NULL value.
I am guessing this is a feature to improve memory usage but is there anyway to turn it off? Or if not is there a work around?
InputCell *inputCell = (InputCell *)[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:i inSection:0]];
UITextField *cellContent = (UITextField *)[inputCell.textInput viewWithTag:0];
NSLog(#"Cell Content: %#" , cellContent.text);
Thanks and thanks again!
Views need models, especially table views. A model is some object (often a group of objects in collection classes) that represents the state of your app. A table view requires an array. The datasource protocol asks you to describe that array. Since tableview cells are part of the view, they shouldn't be relied upon to keep the state of your app. That's up to you as follows:
In your vc's private interface:
#property(strong, nonatomic) NSMutableArray *myDatasource;
Early, like in view did load:
myDatasource = [NSMutableArray array];
// fill it with strings
In numberOfRowsInSection...:
return self.myDatasource.count;
In cellForRowAtIndexPath:
cellContent.text = self.myDatasource[indexPath.row];
Make the vc your textField's delegate and implement:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSString *candidateString = [textField.text stringByReplacingCharactersInRange:range withString:string];
NSIndexPath *indexPath = [self indexPathWithSubview:textField];
self.myDatasource replaceObjectAtIndex:[indexPath.row] withObject: candidateString];
return YES;
}
This helper finds the indexPath of any textField (any subview) of any cell:
- (NSIndexPath *)indexPathWithSubview:(UIView *)subview {
while (![subview isKindOfClass:[UITableViewCell self]] && subview) {
subview = subview.superview;
}
return [self.tableView indexPathForCell:(UITableViewCell *)subview];
}
It looks like a lot, but not so bad when you get used to it. The pattern is always - think of the objects that describe the state of your app (model). Think of views that best describe and manipulate that state (view). Make your view controllers (controllers) (a) notice model changes and change the views accordingly, and (b) hear about user actions from the views and update the model.
I am a newbie to iOS development. I have gone through a couple of tutorials and know the basics, but currently I am stuck on how to proceed further. I am planning to create an app for basic home automation (i.e. switching lights, measuring temperature etc.). The backend is all set, so this is just about the frontend. This is what I am planning to do:
The main view of the app should display a floor plan or the layout of the house
On this floor plan you should be able to add lights/sensors/etc. - lets say objects to keep it generic
These objects should be draggable so that you can arrange them on the floor plan according to where they really are (physically) - ideally this drag mode is toggable similar to rearranging icons on the home screen
Each object should have a popover view (i.e. to set the dimmer intensity, switch lights etc.)
I know there is a lot of work to do, but I don't really know how to set this up. Current alternatives:
Create a custom UIView subclass that contains all the logic an do the drawing in custom code, i.e. the dragging, the popover positioning etc. - but I have the feeling that I wouldn't really be leveraging the iOS framework capabilities
Display the floor plan as an UIImageView and one UIButton for each object. This has the advantage that I can use StoryBoard to do the layouting and wiring (i.e. create segues for popovers etc.) - but I simply can't figure out how to do this with a variable number of buttons (since I don't know in advance how many buttons there will be). Is there some way to create these buttons in code?
Use a custom UITableView. I have seen a couple of examples where they seem to use table views even if the layout has nothing to do with tables (like in my example) but I haven't found any tutorials that explain this concept in more detail
Or am I totally on the wrong track? Any input is appreciated.
Thanks
D.
UPDATE:
After some more research and thought on this I think the way to go with iOS 6 is to use an UICollectionView with a custom layout. Once I have come up with a complete solution I will post it here. For older iOS versions I think it would be promising to go with Option Nr. 2 - i.e. creating each UIButton (for the automation objects e.g. lights) in code and having a custom UIView subclass to do the layouting of these buttons.
Ok I think UICollectionView is ideal for this usage scenario and I am just lucky to have started with iOS programming just as it was introduced to the framework. The following example is a UICollectionView that displays its elements according to their inherent coordinates. This example could also be applied to positioning objects on a map. I couldn't find any examples elsewhere so I'll post the main steps here (since I am a beginner please correct any mistakes).
To start off I created a simple project with one view and storyboard in XCode. I removed the standard view and inserted a Collection View Controller instead and configured my UICollectionViewController subclass as the class that should be used (in the properties of the controller in storyboard).
For the demo just set the background of the default UICollectionViewCell to a color and set the Identifier to "AutomationCell" for this example (if you change it be sure to adjust the code below).
First I create a simple object with some properties that represents an object that should be displayed on the floor plan:
#interface AULYAutomationObject : NSObject
#property NSString *title;
#property CGPoint position;
#end
Then I need my own delegate as subclass to the standard UICollectionViewDelegate since my custom UICollectionViewLayout will not have direct access to the dataSource objects. Therefore I provide a method that will give me the position of the object:
#protocol AULYAutomationObjectLayoutDelegate <UICollectionViewDelegate>
- (CGPoint)getPositionForItemAtIndexPath:(NSIndexPath *)indexPath;
#end
Make sure to implement this protocol in your controller like this:
#interface AULYViewController : UICollectionViewController <AULYAutomationObjectLayoutDelegate>
Then I implemented the standard datasource and delegate methods along with my custom one in the view controller subclass:
#interface AULYViewController ()
#property NSArray *objects;
#property (strong, nonatomic) IBOutlet UICollectionView *collectionView;
#end
#implementation AULYViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Set up the data source
NSMutableArray *automationObjects = [[NSMutableArray alloc] initWithCapacity:10];
// add some objects here...
self.objects = [automationObjects copy];
UILongPressGestureRecognizer *longPressRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(handleTapGesture:)];
[self.collectionView addGestureRecognizer:longPressRecognizer];
}
#pragma mark - UICollectionViewController
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return self.objects.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
AULYAutomationObjectViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"AutomationCell" forIndexPath:indexPath];
// If you have a custom UICollectionViewCell with a label as outlet
// you could for example then do this:
// AULYAutomationObject *automationObject = self.objects[indexPath.row];
// cell.label.text = automationObject.title;
return cell;
}
#pragma mark - AULYAutomationObjectLayoutDelegate
- (CGPoint)getPositionForItemAtIndexPath:(NSIndexPath *)indexPath
{
AULYAutomationObject *automationObject = self.objects[indexPath.item];
return automationObject.position;
}
In a real project you would probably do some conversion from the object model position to the position on screen (e.g. GPS data to pixels) but here this is left out for simplicity.
After having done that we still need to set up our layout. This has the following properties:
#interface AULYAutomationObjectLayout : UICollectionViewLayout
#property (nonatomic, strong) NSIndexPath *draggedObject;
#property (nonatomic) CGPoint dragPosition;
#end
And the following implementation:
#implementation AULYAutomationObjectLayout
- (void)setDraggedObject:(NSIndexPath *)draggedObject
{
_draggedObject = draggedObject;
[self invalidateLayout];
}
- (void)setDragPosition:(CGPoint)dragPosition
{
_dragPosition = dragPosition;
[self invalidateLayout];
}
- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewLayoutAttributes *layoutAttributes = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
id viewDelegate = self.collectionView.delegate;
if ([viewDelegate respondsToSelector:#selector(getPositionForItemAtIndexPath:)])
{
CGPoint itemPosition = [viewDelegate getPositionForItemAtIndexPath:indexPath];
layoutAttributes.center = itemPosition;
layoutAttributes.size = CGSizeMake(ITEM_SIZE, ITEM_SIZE);
}
if ([self.draggedObject isEqual:indexPath])
{
layoutAttributes.center = self.dragPosition;
layoutAttributes.transform3D = CATransform3DMakeScale(1.5, 1.5, 1.0);
layoutAttributes.zIndex = 1;
}
return layoutAttributes;
}
- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
{
NSMutableArray *allAttributes = [[NSMutableArray alloc] initWithCapacity:4];
for (NSInteger i = 0; i < [self.collectionView numberOfItemsInSection:0]; i++)
{
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:0];
UICollectionViewLayoutAttributes *layoutAttributes = [self layoutAttributesForItemAtIndexPath:indexPath];
[allAttributes addObject:layoutAttributes];
}
return allAttributes;
}
- (BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)newBounds
{
return YES;
}
- (CGSize)collectionViewContentSize
{
return [self.collectionView frame].size;
}
#end
To set the custom layout in the storyboard just go to the properties of the controller view and select custom as the layout type - then select your custom class.
Now to enable drag and drop support with the long press gesture simply add the following to your controller:
- (void)handleTapGesture:(UITapGestureRecognizer *)sender
{
AULYAutomationObjectLayout *automationLayout = (AULYAutomationObjectLayout *)self.collectionView.collectionViewLayout;
if (sender.state == UIGestureRecognizerStateBegan)
{
CGPoint initialPinchPoint = [sender locationInView:self.collectionView];
NSIndexPath* tappedCellPath = [self.collectionView indexPathForItemAtPoint:initialPinchPoint];
[self.collectionView performBatchUpdates:^{
automationLayout.draggedObject = tappedCellPath;
automationLayout.dragPosition = initialPinchPoint;
} completion:nil];
}
else if (sender.state == UIGestureRecognizerStateChanged)
{
automationLayout.dragPosition = [sender locationInView:self.collectionView];
}
else if (sender.state == UIGestureRecognizerStateEnded)
{
AULYAutomationObject *automationObject = self.objects[automationLayout.draggedObject.item];
automationObject.position = [sender locationInView:self.collectionView];
[self.collectionView performBatchUpdates:^{
automationLayout.draggedObject = nil;
automationLayout.dragPosition = CGPointMake(0.0, 0.0);
} completion:nil];
}
}
One important note:(this cost me at least an hour): When using the transform3D you should make sure to import QuartzCore into your linked frameworks (in the project properties below the orientation settings). Otherwise you will get a Mach-O Linker Error saying that _CATransform3DMakeScale can not be found.
Hey guys, so in my newest program I use an NSTableView to display words on the left, and thier definitions on the right. these words and definitions are load from a .plist file, and at application startup the table view loads these words and definitions and displays them just fine. My problem comes in when the user tries to add a word and definition using the text boxes and buttons, the word is actually added to the .plist, meaning the method is running fine, but the table view refuses to display the new line. only until after i quit the program and reopen it does the tableview display the new line. I tested to see if the table view was connected properly by sending it other messages such as selectedRow and dataSource, all came back with responces, and proper responces at that. Currently the class that is used as the dataSource and delegate is a subclass to my main class with all my varibles and dictionaries. (I am big on using as little classes as possible). Lastly I tried inserting noteNumberOfRowsChanged in before reloadData, but still nothing.
I have tested everything and it just seems that the reloadData method is not initiating anything. Like I said, my table view is being sent the message, the new info is actually being added to the dicitinoary adn array, the amount of rows is being updated by the count method, and what proves it even more is that when the program is restarted it displays everything just fine. below is the relevent code, where currentWordList and currentDefitionList are the Array and Dictionary suppying the data to the dataSource, and editLibraryCardList is the NSTableView I am trying to reload.
the dataSource class code:
#interface EditorDataTable : SAT_Vocab_MacController {
IBOutlet NSTableColumn *editLibraryWordColumn;
IBOutlet NSTableColumn *editLibraryDefinitionColumn;
}
- (int)numberOfRowsInTableView:(NSTableView *)tableView;
- (id)tableView:(NSTableView *)tableView objectValueForTableColumn:(NSTableColumn *)tableColumn row:(int)row;
#end
#implementation EditorDataTable
- (int)numberOfRowsInTableView:(NSTableView *)tableView {
return ([currentWordList count]);
}
- (id)tableView:(NSTableView *)tableView objectValueForTableColumn:(NSTableColumn *)tableColumn row:(int)row {
if (tableColumn == editLibraryWordColumn) {
return [currentWordList objectAtIndex:row];
}
if (tableColumn == editLibraryDefinitionColumn) {
return [currentDefinitionList valueForKey:[[currentWordList objectAtIndex:row]lowercaseString]];
}
}
#end
method that adds the word to the list:
- (IBAction) editLibraryAddWordToLibrary: (id) sender {
if (self = [super init]) {
currentWordList = [[NSArray alloc] initWithContentsOfFile:userSATWordListPath];
currentDefinitionList = [[NSDictionary alloc] initWithContentsOfFile:userSATDefinitionListPath];
}
[currentWordList addObject:[[editLibraryNewCardWordInput stringValue]capitalizedString]];
[currentDefinitionList setObject:[editLibraryNewCardDefinitionInput stringValue] forKey:[[editLibraryNewCardWordInput stringValue]lowercaseString]];
aWordCounter = [currentWordList indexOfObject:[[editLibraryNewCardWordInput stringValue]capitalizedString]];
[aWordLabel setStringValue: [[NSString alloc] initWithFormat:#"%#", [currentWordList objectAtIndex: aWordCounter]]];
[aDefinitionLabel setStringValue: [[NSString alloc] initWithFormat:#""]];
[currentWordList writeToFile:userSATWordListPath atomically:YES];
[currentDefinitionList writeToFile:userSATDefinitionListPath atomically:YES];
[cardCountdownNumber setStringValue: [[NSString alloc] initWithFormat:#"%i", ([currentWordList count] - (1 + aWordCounter))]];
[editLibraryCardList noteNumberOfRowsChanged];
[editLibraryCardList reloadData];
}
Iv'e been stuck for days and any ideas will help! Thanks.
Zach
Have you tried debugging into your selectRowAtIndexPath method to make sure the reload occurs? (after you call [tableView reloadData] should be able to see this) Are you using UITableViewController?
If you wanted a callback after reload to know when its done, you could try:
[tableView reloadData];
[self performSelector:#selector(selectRowAtIndexPath:) withObject:indexPath afterDelay:0.0];
For those who are curious, i moved my code from the dataSource subclass to the main class, and it worked. i guess you cannot subclass the dataSource. Hope this helps!
Up front, let me just say that I know the code I'll be showing below is probably inefficient, but I'm doing this "the hard way" because that's usually how I get things to stick when I'm learning...
I've created a class that I'm calling at runtime and within that is a label (I'll be adding more labels dynamically, etc.) When I check the container that will hold these views, I first check to see if there are any other views within it already. If not, I add the view directly. If there are other views already in there, I need to check that it won't put two of the same item in there. Since these are based on a single class, my current line of madness is to use the "headerLabel" outlet I've set up in the xib for this class. So...
In PhysicalExamDetailsNoteItem.h:
#import <UIKit/UIKit.h>
#interface PhysicalExamDetailsNoteItem : UIViewController {
IBOutlet UILabel *headerLabel;
}
#property(nonatomic, retain)UILabel *headerLabel;
#end
In PhysicalExamDetailsNoteItem.m, I add: #synthesize headerLabel; after #implementation.
In ViewController.m:
#import "PhysicalExamDetailsNoteItem.h"
// ... And after a long list of code-based view setup, I call a method that includes the following ... //
if([[physExamDetailsNoteItems subviews] count] > 0)
{
NSLog(#"More than one item already exists in the container, check preexisting items for %# to eliminate duplication...", sender.currentTitle);
for (PhysicalExamDetailsNoteItem *subview in [physExamDetailsNoteItems subviews]) {
NSLog(#"subview.headerLabel.text = %#", subview.headerLabel.text);
if (subview.headerLabel.text != sender.currentTitle) {
NSLog(#"%# doesn't exist in the container, add it as a new item...", sender.currentTitle);
PhysicalExamDetailsNoteItem *noteItem;
noteItem = [[PhysicalExamDetailsNoteItem alloc] initWithNibName:#"PhysicalExamDetailsNoteItem" bundle:[NSBundle mainBundle]];
[physExamDetailsNoteItems addSubview:noteItem.view];
noteItem.headerLabel.text = sender.currentTitle;
}
}
}
else
{
NSLog(#"No items exist in the container, add a new item...");
PhysicalExamDetailsNoteItem *noteItem;
noteItem = [[PhysicalExamDetailsNoteItem alloc] initWithNibName:#"PhysicalExamDetailsNoteItem" bundle:[NSBundle mainBundle]];
[physExamDetailsNoteItems addSubview:noteItem.view];
noteItem.headerLabel.text = sender.currentTitle;
}
I'm getting the error at this section:
PhysicalExamDetailsNoteItem *subview in [physExamDetailsNoteItems subviews]) {
NSLog(#"subview.headerLabel.text = %#", subview.headerLabel.text);
I have the headerLabel outlet rigged from the File's Owner object to the label view within IB, and when the enclosing method runs the if condition for the first time, it uses the else clause and populates my container view and changes the label text just as I want it to, but once it is called again and looks for the headerLabel for a comparison, it bails and I get:
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIView headerLabel]: unrecognized selector sent to instance 0x4b17470'
Thanks in advance!
Because you are asking for all subviews, you are really getting all subviews. Clearly one or more of them are not of the class you are looking for. It's generally not safe to count on subviews of a given view to only be the views you have added yourself.
You should definitely change your fast enumeration declaration to use the UIView class as suggested by ennuikiller. But the fix to your crash will be to test that a given subview is of the expected class before calling your method on it, like so:
for (UIView * subview in [physExamDetailsNoteItems subviews]) {
if ([subview isKindOfClass:[PhysicalExamDetailsNoteItem class]]) {
PhysicalExamDetailsNoteItem * noteItem = (PhysicalExamDetailsNoteItem *)subview;
NSLog(#"noteItem.headerLabel.text = %#", noteItem.headerLabel.text);
}
}
This way, you'll use the dynamic runtime to ensure that the objects you're operating on are they type you expect.
I think your need to declare the fast enumeration like so:
for (UIView *subview in [physExamDetailsNoteItems subviews]) {
and not as
PhysicalExamDetailsNoteItem *subview in [physExamDetailsNoteItems subviews])
After all you are processing UIView, not UIViewControllers.
Okay, I've got a custom class called "Task", which represents a task to be done. I've got an NSMatrix which acts as a calendar. I want the user to be able to drag an icon from an nscollectionview (I've had no trouble setting up the nscollectionview) onto a cell in the nsmatrix, thereby assigning that task to that day. I just can't seem to get the nsmatrix to respond to the drag or the drop at all.
I've implemented the method:
- (BOOL)collectionView:(NSCollectionView *)cv writeItemsAtIndexes:(NSIndexSet *)indexes toPasteboard:(NSPasteboard *)pasteboard
{
[pasteboard declareTypes:[NSArray arrayWithObject:TASK_UTI] owner:self];
NSUInteger index=[indexes firstIndex];
Task* task=[[cv content] objectAtIndex:index];
NSData* taskData=[NSKeyedArchiver archivedDataWithRootObject:task];
[taskData retain];
BOOL success=[pasteboard setData:taskData forType:TASK_UTI];
return success;
}
in my nscollectionview delegate as shown above.
I've sent [self registerForDraggedTypes:[NSArray arrayWithObjects:TASK_UTI, nil]] in my NSMatrix subclass (called "Calendar").
I've implemented the methods:
- (NSDragOperation)draggingEntered:(id < NSDraggingInfo >)sender
- (BOOL)prepareForDragOperation:(id < NSDraggingInfo >)sender
- (BOOL)performDragOperation:(id < NSDraggingInfo >)sender
in my Calendar (NSMatrix subclass) class.
Some debugging shows that the NSMatrix/Calendar object is not even running the dragging methods above. What gives?
Did you define your Calendar class to implement dragging destination protocol?
First off, you should use your own domain name, not “com.yourcompany”, in the UTI.
Second, did you export the UTI in your Info.plist?