DTGridView losing content while scrolling - iphone

Question

I am using DTGridView from the DTKit by Daniel Tull. I implemented it in a very simple ViewController and the test I am doing is to place a button in the last row of the grid, which should add another row to the grid (and therefor moving the button to a row beneath it).
The problem is, when I click the button a couple of times and then start scrolling, the grid seems to lose its content. As I am not completly sure this is a bug in the grid, but more in my code, I hope you guys can help me out and track down the bug.
First I have my header file, which is quite simple, because this is a test:
#import <UIKit/UIKit.h>
#import "DTGridView.h"
#interface TestController : UIViewController <DTGridViewDelegate, DTGridViewDataSource>
{
DTGridView* thumbGrid;
}
#end
I declare a DTGridView, which will be my grid, where I want to put content in.
Now, my code file:
#import "TestController.h"
#implementation TestController
int rows = 1;
- (NSInteger)numberOfRowsInGridView:(DTGridView *)gridView
{
return rows;
}
- (NSInteger)numberOfColumnsInGridView:(DTGridView *)gridView forRowWithIndex:(NSInteger)index
{
if (index == rows - 1)
return 1;
else
return 3;
}
- (CGFloat)gridView:(DTGridView *)gridView heightForRow:(NSInteger)rowIndex
{
return 57.0f;
}
- (CGFloat)gridView:(DTGridView *)gridView widthForCellAtRow:(NSInteger)rowIndex column:(NSInteger)columnIndex
{
if (rowIndex == rows - 1)
return 320.0f;
else
return 106.6f;
}
- (DTGridViewCell *)gridView:(DTGridView *)gridView viewForRow:(NSInteger)rowIndex column:(NSInteger)columnIndex
{
DTGridViewCell *view = [[gridView dequeueReusableCellWithIdentifier:#"thumbcell"] retain];
if (!view)
view = [[DTGridViewCell alloc] initWithReuseIdentifier:#"thumbcell"];
if (rowIndex == rows - 1)
{
UIButton* btnLoadMoreItem = [[UIButton alloc] initWithFrame:CGRectMake(10, 0, 301, 57)];
[btnLoadMoreItem setTitle:[NSString stringWithFormat:#"Button %d", rowIndex] forState:UIControlStateNormal];
[btnLoadMoreItem.titleLabel setFont:[UIFont boldSystemFontOfSize:20]];
[btnLoadMoreItem setBackgroundImage:[[UIImage imageNamed:#"big-green-button.png"] stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0] forState:UIControlStateNormal];
[btnLoadMoreItem addTarget:self action:#selector(selectLoadMoreItems:) forControlEvents:UIControlEventTouchUpInside];
[view addSubview:btnLoadMoreItem];
[btnLoadMoreItem release];
}
else {
UILabel* label = [[UILabel alloc] initWithFrame:CGRectMake(10,0,100,57)];
label.text = [NSString stringWithFormat:#"%d x %d", rowIndex, columnIndex];
[view addSubview:label];
[label release];
}
return [view autorelease];
}
- (void) selectLoadMoreItems:(id) sender
{
rows++;
[thumbGrid setNeedsDisplay];
}
- (void)viewDidLoad
{
[super viewDidLoad];
thumbGrid = [[DTGridView alloc] initWithFrame:CGRectMake(0,0, 320, 320)];
thumbGrid.dataSource = self;
thumbGrid.gridDelegate = self;
[self.view addSubview:thumbGrid];
}
- (void)viewDidUnload
{
[super viewDidUnload];
}
- (void)dealloc {
[super dealloc];
}
#end
I implement all the methods for the DataSource, which seem to work. The grid is filled with as many rows as my int 'rows' ( +1 ) has. The last row does NOT contain 3 columns, but just one. That cell contains a button which (when pressed) adds 1 to the 'rows' integer.
The problem starts, when it starts reusing cells (I am guessing) and content start disappearing. When I scroll back up, the UILabels I am putting in the cells are gone.
Is there some bug, code error, mistake, dumb-ass-move I am missing here? Hope anyone can help.

Answer 1

I've had a quick look at the code and you should definitely be calling reloadData instead of setNeedsDisplay in selectLoadMoreItems like so:
- (void) selectLoadMoreItems:(id) sender {
rows++;
[thumbGrid reloadData];
}
Let me know if this fixes it, if not I'll take a proper look through your code later today.

Answer 2

There's a pull request that seems to solve this issue. The bottom line is calling initialiseViews everytime checkViews is called.