I try to make cells expand/collapse with drop-down like animation, so when table view recalculates height it moves down other cells below the one that was tapped,
but if the tapped cell top margin is not entirely visible, table view changes its height update behavior by moving all above cells up:
http://imgur.com/CldzuFf
Is there a way to make cells expand with top-to-bottom behavior always?
Reloading cells like this:
[self.tableView beginUpdates];
[self.tableView reloadRowsAtIndexPaths:arrayToReload withRowAnimation:UITableViewRowAnimationBottom];
[self.tableView endUpdates];
Just set the contentOffset based on selected row
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell * theCell = (UITableViewCell *)[tableView
cellForRowAtIndexPath:indexPath];
CGPoint tableViewCenter = [tableView contentOffset];
tableViewCenter.y += myTable.frame.size.height/2;
[tableView setContentOffset:CGPointMake(0,theCell.center.y-65) animated:YES]; // need to customize the y offset 65 to your value
// reload row here
}
Related
I want to change a specific UIImageView inside a UITableViewCell with this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self.tableView beginUpdates];
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
UYLTextCell *textCell = (UYLTextCell *)cell;
textCell.selected = YES;
//get and show the image at selected cell
textCell.testImage.image = [UIImage imageNamed:#"image280280.jpg"];
//[tableView reloadRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[self.tableView endUpdates];
}
But what happened is some cell had their image View even though it has not been clicked.
Table views re-use cells. When a cell is scrolled offscreen it is added to a queue, and will be re-used for the next cell to be scrolled onscreen. That means your cell configuration code in tableView:cellForRowAtIndexPath: should be enough to properly configure any cell, including cells that were previously selected at a different indexPath. In tableView:didSelectRowAtIndexPath: store the selected index path in a property and use that property to configure your cell in tableView:cellForRowAtIndexPath:. The image will need to be set in tableView:cellForRowAtIndexPath: whether the cell is selected or not (unless you implement prepareForReuse in your custom cell).
In my app I am trying to display Mkmapview in UITableView. When I tap the cell, it has to expand and show the map. Then if I tap another cell, it should act again expand and show gallery view , the previous cell must collapse and map should be hide.
thanks in advance,
You have to keep track of the state (or height) of the expanding/collapsing cell. Then report that height in tableView:heightForRowAtIndexPath:. Then add the code below to trigger the resizing.
[self.tableView beginUpdates];
[self.tableView endUpdates];
For example:
- (void)toggleMapCell {
_mapCellExpanded = !_mapCellExpanded;
if (_mapCellExpanded)
_mapCellHeight = 200.0;
else
_mapCellHeight = 44.0;
[self.tableView beginUpdates];
[self.tableView endUpdates];
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if ([indexPath isEqualTo:_mapCellIndexPath])
return _mapCellHeight;
else
return 44.0;
}
If you have to re-layout the cell's content. I think the best place is to do it in the cell's layoutSubviews.
I have a tableview. On tap, a cell expands into a form, and I would like the cell to scroll up to start right below the navigation bar. How do I achieve this?
Here's the starting state:
Currently, after tap:
And here's what I want:
You need something like this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Perform cell change height code here
// ...
// After that scroll to this cell
CGFloat sectionHeaderHeight = [self tableView:tableView heightForHeaderInSection:indexPath.section];
CGRect cellFrame = [tableView rectForRowAtIndexPath:indexPath];
[tableView setContentOffset:CGPointMake(0, cellFrame.origin.y - sectionHeaderHeight) animated:YES];
}
scrollToRowAtIndexPath... or scrollToNearestSelectedRow... both take "scroll position" arguments which allow the selection to go to the top, middle or bottom of the table view. That should give you what you want.
I have a UITableView with Dynamic Prototypes.
I implemented the code below so that when I select a row, it will be marked and the previously selected row will be unmarked.
However, for example, the row I selected is displayed in the middle of the screen, then when I scroll up or down, another cell (which is in the same middle position of the screen) is marked. In short, every view, there is a selected cell at the middle.
Please advise.
- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSIndexPath *oldIndexPath = [self.tableView indexPathForSelectedRow];
[self.tableView cellForRowAtIndexPath:oldIndexPath].accessoryType = UITableViewCellAccessoryNone;
[self.tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryCheckmark;
return indexPath;
}
Probably you are overwriting accessoryType in your cellForRowAtIndexPath method - this is called each time table is about to draw new rows which were invisible before (as you described when you scroll up / down).
You need to handle it also in that function and update accessoryType there - otherwise it will randomly reuse a cells with different accessoryTypes.
You are modifying just the visuals of cell, you're not updating the data model. Store the selected index path in a #property somewhere, and adjust accessoryType inside cellForRowAtIndexPath.
I have a custom tableFooterView (it's just an 8px high CoreGraphics arc with a gradient) that I set with the tableFooterView property in viewDidLoad rather than viewForFooterInSection. When setting it with viewForFooterInSection, it floated over the content when it reached the bottom, whereas tableFooterView does what I want it to in that it stays with the UITableView's height.
But when the cells or table view do change in height, the tableFooterView animates to them slowly (about half a second but it's very noticeable). This is pretty awkward since the footer is supposed to look like an extension of the last cell. For instance, when heightForRowAtIndexPath changes the height of a cell, the tableFooterView kind of ghost-floats back. In this screenshot the bottom cell has just been shrunken to its normal size and the footer is floating back.
(As a new user I can't post images but here's the link: http://desmond.imageshack.us/Himg835/scaled.php?server=835&filename=iossimulatorscreenshotj.png&res=landing)
(This content is no longer available, 14/9/15).
It will also float over the content when the height of the last cell is suddenly changed to be larger than it was.
Any pointers? Thanks very much.
Edit: By cells changing in height, I mean through the heightForRowAtIndexPath section:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
Note *currentNote = [self.notes objectAtIndex:indexPath.row];
if (currentNote.associatedCellIsSelected) {
return NORMAL_CELL_FINISHING_HEIGHT*2;
}
return NORMAL_CELL_FINISHING_HEIGHT;
}
Edit 2: In didSelectRowAtIndexPath I make the cell selected (actually the cell's note), begin / end updates as well as call reloadRow for the row that's been selected.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
Note *currentNote = [self.notes objectAtIndex:indexPath.row];
if (currentNote.associatedCellIsSelected == FALSE) {
currentNote.associatedCellIsSelected = TRUE;
[tableView beginUpdates];
[tableView endUpdates];
}
[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; }
I've also made sure that I get the same behavior with a plain rect redColor UIView in place of the Core Graphics footer, with the same results. I wish there was just an easy way to override the footer and tell it to not animate!