Force redraw as resizing NSTableColumn in NSTableView? - objective-c

I've implemented - (CGFloat)tableView:(NSTableView *)tableView heightOfRow:(NSInteger)row in my NSTableView's delegate to resize the height of my table's rows as the width of the leftmost column changes. The problem is that only that column redraws during the resizing (and any column that slide into view during the resize).
This results in the funky visual below after resizing. What I'd like is a way to tell the table view to completely redraw while the user is resizing a column. Right now the most I've been able to do is call setNeedsDisplay after that column finishes resizing.

Check out the NSTableView method noteHeightOfRowsWithIndexesChanged:. You'll need to make an NSIndexSet of the rows whose heights have changed.
update:
In order to have a safe place to call this, you can subclass NSTableColumn to override the setWidth: method. You can then post a custom notification that your table delegate can observe, or you can override the table view also and have the column tell the table to tell its delegate directly.

It may not be the only way, but giving the table view a Core Animation layer fixed it. It's not 100% smooth, but the average user would probably never notice.

Related

NSTableView won't layout / resize columns until NSWindow manually resized

I've an NSTableView with several NSTableColumn objects that appear to have all the correct auto-resizing flags set. However, every time I rebuild the table's contents, the columns all return to a narrow size -- unless I click and manually resize the window.
The NSTableView is inside:
NSWindow
NSView
NSScrollView
NSTableView
(other NSTableView objects: NSTableColumn, NSTextFieldCell, NSScroller (x 2)
Column resizing mask is always:
NSTableColumnAutoresizingMask
NSTableColumnUserResizingMask
The table is created always set with:
[theNSTableView setColumnAutoresizingStyle:NSTableViewUniformColumnAutoresizingStyle];
After reloading the table with data,
[theNSTableView reloadData];
[theNSTableView tile];
...and even:
[theNSTableView setNeedsDisplay:YES];
All views are set to "autoresizesSubviews".
Neither the NSView nor the NSScrollView have any referencing outlets -- could that be the problem?
After discussing this issue at length with Apple Developer Technical Support, they believe there may be an issue with Carbon-Cocoa integration.
However, they also point out that I really should not set NSTableViewUniformColumnAutoresizingStyle and I should be calculating the widths of all my columns in my own code, and then either telling the column to remember its width, or storing the width and making sure to set the same width on each column AFTER I programmatically create the column.
While I can accept this, I had been at least hoping I could programmatically invoke the same method that is called when a user double-clicks on a column divider and the column resizes itself to fit all of its cell text contents. However, DTS tells me those functions are not available.
I have come across other solutions to this issue here on SO and I will see if they can be adapted to create an optimal solution.

Value is shown in UITableView after it is scrolled

In my iPad application, I am inserting some value on a label. That value should also appear on a UITableView in another class. When I insert the value in the label and navigate to another view, there is no value appearing on the table view but when I scroll the table view up and as it comes to its original position, the value appears. How can I fix it?
Thanks and regards
PC
When you scroll the table you are eventually reloading the data as things become visible. If you call [tableView reloadData] on viewillAppear this should get the label refreshed and displaying correctly for you.
Good Luck!
Check out the reloadData method in the documentation. You will need to call this method after changing the value so the table knows to reload the cells currently being displayed. As you scroll up the cells are being redrawn, which is why you see the new value after a scroll.
Just to clarify, the reloadData method will need to be called on the UITableView object.
[myTableView reloadData];
From the documentation:
Reloads the rows and sections of the receiver.
- (void)reloadData
Discussion
Call this method to reload all the data that is used to construct the table, including cells, section headers and footers, index arrays, and so on. For efficiency, the table view redisplays only those rows that are visible. It adjusts offsets if the table shrinks as a result of the reload. The table view's delegate or data source calls this method when it wants the table view to completely reload its data. It should not be called in the methods that insert or delete rows, especially within an animation block implemented with calls to beginUpdates and endUpdates

UITableView in a UIScrollView - How to make the view scroll, but not the TableView in itself?

Imagine, there is a UIViewController with a UIScrollView in it. At the top of the view there is an UIImageView, some UILabels and other things. Furthermore, there is a UITableView which content is Dynamic Prototypes. I attach a picture to make it clear:
I haven't got a static amount of cells in the UITableView so it could be scrollable. My problem is the following: the UITableView scrolls in itself but I want to scroll the whole View. What is the best possibility to do that?
Possible solutions I've founded today
1) The first thing is: I create a UITableViewController and declare a header section in which I include all my labels, images etc. programmatically (I would love to use the interface builder for that...)
2) Another solution is to calculate the height of the view. I tried the best to do it like this way - but: without success. If this is the best way to do that: Can anybody give an example?
I would ditch the UIScrollView and just use a UITableView. You can add a UIView object as the tableHeaderView of the UITableView just by dragging it in in Interface Builder. Now since everything is part of the UITableView hierarchy, everything will scroll together as expected.
You could also try setting delaysContentTouches to NO on your scrollView. Depending on your setup, this may make the scroll view respond to the touch first instead of the table view.
From Apples UIScrollView Docs:
delaysContentTouches
A Boolean value that determines whether the scroll view delays the
handling of touch-down gestures.
#property(nonatomic) BOOL delaysContentTouches
Discussion
If the value of this property is YES, the scroll view delays handling
the touch-down gesture until it can determine if scrolling is the
intent. If the value is NO , the scroll view immediately calls
touchesShouldBegin:withEvent:inContentView:. The default
value is YES.
You'll have to (as you've mentioned) add the UIView containing the image and buttons to the actual UITableView. Embedding it in the scroll view will produce the undesired behavior that you're seeing.
I would recommend returning the UIView as the header view for the first section of your table view. You can do this by implementing the UITableViewDelegate method:
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section;
If you maintain an IBOutlet to the view containing your image/labels, you can return it here.
this is same demo i hope its helps you from iphone sorce code library
http://developer.apple.com/library/ios/#samplecode/iPhoneCoreDataRecipes/Introduction/Intro.html
thank you

mouseover detection in NSTableView's NSCell?

I am wanting to change the text background color on a tableview's cell when it is hovered upon, similar to how AddressBook "highlights" the label of a contact's element when you mouseover the label names. However I cannot figure out how to accomplish...
detecting a mouseover on a particular NSCell and...
After detecting the cell his hovered upon, highlighting the text in that cell (not highlighting the entire row as if the user selected that row)
As NSCell is not a subclass of NSView this seems to be a very difficult task.
Any example of this or explanation on how this might be done would be greatly appreciated.
Thanks!
I actually got it working using another method. I got it from the example posted here... http://www.cocoadev.com/index.pl?NSTableViewRollover
https://web.archive.org/web/20111013060111/http://cocoadev.com/index.pl?NSTableViewRollover
Instead of using NSCell's tracking mechanism, I am tracking mouseEntered/mouseExited and mouseMoved within my subclassed NSTableView.
When the tableview awakeFromNib method is called, I create a trackingRect from the visible portion of the tableview
I have a BOOL ivar that is set to YES when the mouse is within the tracking area(mouseEntered) and NO when it is not (mouseExited)
Within the mouseMoved method, I determine the current row the mouse cursor is on and set it to an NSInteger ivar and then call the tableview's setNeedsDisplayInRect: passing the rect of the row that the mouse is on.
I also override resetCursorRects to remove the old tracking rect and add a new one...this method is called when the tableview is scrolled upon so that it's tracking the latest visible rect.
Finally in my tableview's delegate, I determine the selected row (by retrieving the row index from the NSInteger ivar of the table view and change the cell's text color (or anything you want) if the currently drawn cell matches the row the mouse cursor is on. All this is done in the delegate method: tableView:(NSTableView *)aTableView willDisplayCell:(id)aCell forTableColumn:(NSTableColumn *)aTableColumn row:(NSInteger)rowIndex
I hope this helps others, as this was a bit tricky. It is also probably important to make sure that tableview is the firstResponder when the view loads, just makes things a bit more streamlined and cleaner.
Btw, is there a way to make a specific control in a view always be the firstResponder with nothing else possible as being the firstResponder? Even a method such as the iPhones... viewWillAppear method will help as I could set the first responder each time the view is visible...but i'm not aware of such a method on the Mac.
Overall, it's not a simple task as you noticed.
To track the mouse in an NSCell, subclass NSCell and override
-[NSCell startTrackingAt:inView:]
and
-[NSCell stopTracking:at:inView:mouseIsUp:]
Once you've detected the mouse is tracking inside a cell, you can find out which cell you are in the table with [tableView rowAtPoint:point] and [tableView columnAtPoint:point], and then find your frame with [tableView frameOfCellAtColumn:column row:row]
Then, you can change the way your cell is drawn by changing some property of the cell or changing the way it's drawn directly by overriding drawInteriorWithFrame:inView:.
Here's documentation on subclassing NSCell:
http://developer.apple.com/mac/library/documentation/cocoa/conceptual/ControlCell/Tasks/SubclassingNSCell.html
I achieved something similar by making use of addGlobalMonitorForEventsMatchingMask: handler: of NSEvent within my NSTableView subclass for the NSMouseMovedMask. using this along with columnAtPoint and rowAtPoint of NSTableView I was able to figure out if the position of the mouse was within a given cell.
Using this information I was able to bring up a PopOver when the mouse was over a particular cell.

Scrolling in NSTableView

I'm not asking how to do this, it's more in line of "What would you call this?".
I have an NSTableView with several custom cells. I want the table to scroll row by row, meaning that when I move the scrollbar up I want the top row to disappear and when I move it down I want the bottom row also to disappear - I don't want to see half my cell.
How do you call this type of behavior? And can you share some pointers if you've implemented it in a NSTableView?
I'm not exactly sure what this would be called (maybe something like "constrained scrolling"?), but you can do it using NSView's -adjustScroll: method.
The general approach is that you need to make a subclass of NSTableView (if you don't already have one), and override this method to return a NSRect that has its origin.y value constrained to a multiple of your row height.
You probably also want to use NSScrollView's -setVerticalLineScroll: to set the proper amount to scroll when the user clicks the scroll arrows in the vertical scroll bar. You can get the scrollView by calling -enclosingScrollView on your tableView.