Selecting Table Area

Operating system requirements: iOS 5.0 or later.

Mobile device: iPad.

Description

This example describes selecting of table area. After starting the example the following operations are executed:

The specified table cell range is selected.
A text aligned by center and informing about cell selection is displayed above the selection.
This text disappears in three seconds, table cell selection remains.

Source Code

Executing the example requires to place the following code instead of the executeExample method of the ViewController class (see the Creating a Simple Data Grid section):

-(void)executeExample {
    // Enable table selection
    [contr setCanSelect:YES];
    [[contr gridView] setCanSelect:[contr canSelect]];
    // Select table area
    NuGridView *gridView = [contr gridView];
    [contr selectAreaFromRow:[gridView rowWithNumber:1] column:[gridView columnWithNumber:1]
    toRow:[gridView rowWithNumber:2] column:[gridView columnWithNumber:2]];
};
// Called after table area is selected
- (void)gridView:(NuGridView *)gridView areaSelected:(NuGridSelectionArea *)area
{
    // Determine label position and size
    CGRect rect = [area bounds];
    CGPoint position = [area center];
    rect.origin.x = position.x - rect.size.width/2;
    rect.origin.y = position.y - rect.size.height/2;
    // Create a label
    [self showViewWithText:@"Area selected" inRect:rect];
}
-(void)showViewWithText:(NSString*)text inRect:(CGRect)rect {
    UILabel *label = [[UILabel new] autorelease];
    label.textColor = [UIColor redColor];
    [label setText:text];
    // Align text by center
    [label setTextAlignment:NSTextAlignmentCenter];
    [label setFrame: rect];
    // Display label
    [[contr gridView] addSubview:label];
}
// Removes displayed element
- (void)hideView:(UIView *)view {
    [view removeFromSuperview];
}
// Called before table layout change
- (void)gridViewActionBeforeLaying:(NuGridView *)gridView {
    if([gridView canSelect]) {
        // Display label with message about table area selection
        [self gridView:gridView areaSelected:[gridView selectionArea]];
        [gridView setCanSelect:NO];
    }
}
// Called after table layout change
- (void)gridViewActionAfterLaying:(NuGridView *)gridView {
    for (UIView *view in [gridView subviews]) {
        if([view isKindOfClass:[UILabel class]]) {
            // Hide all labels in three seconds
            [self performSelector:@selector(hideView:) withObject:view afterDelay:3.0];
        }
    }
}

After executing the example the table cell range is selected that covers rows and columns having the numbers 1 and 2. A text label aligned by center and informing about cell selection is displayed above the selection:

This text disappears in three seconds, table cell selection remains: