CollectionViews

Language: Hydrogene, Platform: Toffee, Category: UIKit
https://github.com/remobjects/ElementsSamples/tree/master/Hydrogene/Toffee/UIKit/CollectionViews

• CollectionViews
  • References
    • CoreGraphics
    • Foundation
    • UIKit
    • rtl
    • libToffee
  • Source Files
    • AppDelegate.cs
    • Program.cs
    • RootViewController.cs
  • Other Files
    • Resources\Info.plist
    • Resources\App Icons\App-29.png
    • Resources\App Icons\App-48.png
    • Resources\App Icons\App-57.png
    • Resources\App Icons\App-58.png
    • Resources\App Icons\App-72.png
    • Resources\App Icons\App-96.png
    • Resources\App Icons\App-114.png
    • Resources\App Icons\App-144.png
    • Resources\App Icons\App-512.png
    • Resources\App Icons\App-1024.png
    • Resources\Launch Images\Default.png
    • Resources\Launch Images\Default@2x.png
    • Resources\Launch Images\Default-568h@2x.png
    • Resources\Launch Images\Default-Portrait.png
    • Resources\Launch Images\Default-Portrait@2x.png
    • Resources\Launch Images\Default-Landscape.png
    • Resources\Launch Images\Default-Landscape@2x.png

RootViewController.cs

namespace CollectionViews
{
	using UIKit;

	class RootViewController : UICollectionViewController
	{
		private const string CELL_IDENTIFIER = "RootViewController_Cell";
		private const string HEADER_IDENTIFIER = "RootViewController_Header";
	
		private NSArray data;
		
		private UICollectionViewFlowLayout collectionViewFlowLayout { get { return collectionView.collectionViewLayout as UICollectionViewFlowLayout; } }


		public override id init()
		{
			this = base.initWithCollectionViewLayout(new UICollectionViewFlowLayout());
			if (this != null)
			{
				title = "Collection View Sample";
				collectionView.registerClass(UICollectionViewCell.@class) forCellWithReuseIdentifier(CELL_IDENTIFIER);
				collectionView.registerClass(UICollectionReusableView.@class) forSupplementaryViewOfKind(UICollectionElementKindSectionHeader) withReuseIdentifier(HEADER_IDENTIFIER);
				collectionViewFlowLayout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);
				collectionViewFlowLayout.headerReferenceSize = CGSizeMake(40, 40); // only one dimension is used at a time
			}
			return this;
		}

		public override void viewDidLoad()
		{
			base.viewDidLoad();

			// set up the (random) data to display in the collection view.
			
			// to avoid blocking the main thread and application startup, we do this in a block on a
			// background thread. Once done, we dispatch mach to the main thread to trigger a reload.
			
			dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), () => {
			
				var lArray = new NSMutableArray();
				for (Int32 i; i <= arc4random_uniform(5)+5; i++)
				{
				
					var lSection = new NSMutableArray();
					for (Int32 j; j <= arc4random_uniform(50)+5; j++)
					{
					
					  var lSize = arc4random_uniform(100) + 100;
					  lSection.addObject(lSize);
					
					}
					lArray.addObject(lSection);
				
				}
				
				data = lArray;
				dispatch_async(dispatch_get_main_queue(), () => collectionView.reloadData());
			
			});
		}

		public override void didReceiveMemoryWarning()
		{
			base.didReceiveMemoryWarning();
		   // Dispose of any resources that can be recreated.
		}
		
		#region Collection view data source}
		public NSInteger numberOfSectionsInCollectionView(UICollectionView collectionView)
		{
			if (data != null) return data.count;
			return 0;
		}
		
		public NSInteger collectionView(UICollectionView collectionView) numberOfItemsInSection(NSInteger section)
		{
			if (data != null) return data[section].count;
			return 0;
		}
			
		public UICollectionViewCell collectionView(UICollectionView collectionView) cellForItemAtIndexPath(NSIndexPath indexPath)
		{
			var result = collectionView.dequeueReusableCellWithReuseIdentifier(CELL_IDENTIFIER) forIndexPath(indexPath);
			
			// remove any existing sub-views, in case we are reusing an existing cell
			result.subviews.makeObjectsPerformSelector(__selector(removeFromSuperview));
			
			// and then add a label to the cell showing the current item number.
			var lLabel = new UILabel();
			lLabel.text = NSNumber.numberWithInt(indexPath.row).stringValue;
			lLabel.frame = result.bounds;
			lLabel.textColor = UIColor.whiteColor;
			lLabel.backgroundColor = UIColor.darkGrayColor;
			lLabel.font = UIFont.systemFontOfSize(30);
			lLabel.textAlignment = NSTextAlignment.NSTextAlignmentCenter;
			result.addSubview(lLabel);
			
			return result;
		}
		
		public CGSize collectionView(UICollectionView collectionView) layout(UICollectionViewLayout aCollectionViewLayout) sizeForItemAtIndexPath(NSIndexPath indexPath)
		{
			// each cell will have a random size
			var lInfo = data[indexPath.section][indexPath.row];
			return CGSizeMake(lInfo.floatValue, lInfo.floatValue);
		}

		public UICollectionReusableView collectionView(UICollectionView collectionView) viewForSupplementaryElementOfKind(String kind) atIndexPath(NSIndexPath indexPath)
		{
			var result = collectionView.dequeueReusableSupplementaryViewOfKind(kind) withReuseIdentifier(HEADER_IDENTIFIER) forIndexPath(indexPath);
			
			// remove any existing sub-views, in case we are reusing an existing cell
			if (result.subviews != null)
				result.subviews.makeObjectsPerformSelector(__selector(removeFromSuperview));
			
			// and then add a label to the cell showing the current section.
			var lLabel = new UILabel();
			lLabel.text = NSString.stringWithFormat("Section %ld", indexPath.section);
			lLabel.frame = result.bounds;
			lLabel.textColor = UIColor.blackColor;
			lLabel.backgroundColor = UIColor.lightGrayColor;
			lLabel.font = UIFont.boldSystemFontOfSize(20);
			lLabel.textAlignment = NSTextAlignment.NSTextAlignmentCenter;
			lLabel.contentMode = UIViewContentMode.UIViewContentModeRedraw;
			result.addSubview(lLabel);
			
			return result;
		}
		#endregion

		#region Collection view delegate
		public void collectionView(UICollectionView collectionView) didSelectItemAtIndexPath(NSIndexPath indexPath)
		{
			// add code here to handle when a cell gets selected.
		}
		#endregion



	}
}