Can NSsliderCell work in "continuous" mode when inside a TableView? - cocoa

Is it possible for a NSSliderCell to work in "continuous" mode when inside a cell-based NSTableView? I've searched here on S.O. and also googled the question without seeing anything directly relevant.
In Interface Builder I have checked the "continuous' properties for both the Slidercell and the TableView, but I cannot get the slider to send out continuous messages.
I have no problem using NSSlider controls in continuous mode elsewhere in my application, and the Slidercell/Tableview in question here works fine as is, but updates only when the mouse is released.
Is it necessary to use a View-based Tableview to get this behaviour? I would rather not do that because it means a messy rewrite of the code for several other tableviews as well.
(edit)
The below code is in VFX Forth, using their provided Cocoa bridge. The relevant portion in tableView:setObjectValue:forTableColumn:row: is :
" BPAd" theid$ #isEqualToString:
?of objectid #floatValue
phr# paraatom# PHRASE.ATOM#>A +atomExtra 04 + SF!
endof
" BPad" is the identifier for the column containing the slider cell.
'The next line just takes the floatValue from the slider and stores in into my data-structure.
The above all works exactly as expected, but ONLY on release of the mouse-button. It does not act continuously.
thanks in advance for any insight

Related

What is the appropriate UI set up for messaging functionality?

I have an app which allows users to send messages to each. The process is accomplished by saving the sent messages in a local SQLite database, while actually sending the messages to a database and using push notifications to send the message to the recipient's SQLite database. The set up I have works fine. However, what I am confused about is how to set up the actual interactive UI for the user (I am using XCode). I figured it should be a UITableView with each table cell representing a message. However, with this approach I run into a few requirements:
Variable TextView Sizes
Just as with regular iOS messaging, the TextView's size needs to be variable, adjusting its dimensions to fit all of the text in each message. I do not know how to accomplish this. I have a general understanding of how to generally vary sizes, but no clue how to dynamically have it based on the text within that view.
Variable TextView Positions
Again, just as with regular iOS messaging, the textview needs to be offset to either the right or left side depending on whether the sender was the user or who the are conversing with, respectively. I also do not know how to do this, because it changes the center of the textview.
Non-selectability
Xcode allows cells to be pressed. Handling what happens after this selection can be achieved by the didSelectRowatIndexPath tableView function. I can simply not implement this, but clicking on the cell causes it to turn darker to indicate it has been pressed. I would like to eliminate this while retaining the ability to, say, select some of the text and copy and paste it or whatever (just like messaging works normally on your phone).
Other Approaches?
This is the real meat of the question. I have considered the above approach because that is all that I have been able to come up with based on my limited experience with XCode UI elements. If there is a better approach (perhaps even a pod or framework) for this purpose I would love to hear it. I do not need the messaging UI to look amazing, just clean and crisp.
I suggest the following:
Variable TextView Sizes:
I assume you do use auto layout. If you don’t yet, please consider using it since it make life much easier!
If you use a UITableView, you can adjust the height of its UITableViewCells dynamically, depending on the actual content by using self-sizing cells. You can find a tutorial how to do this here.
Variable TextView Positions:
I assume you have a UITextView within a table view cell. In this case, you have to set auto layout constraints to the borders of the cell’s contentView. If you define a custom subclass of a UITableViewCell, you can define in this class 2 IBOutlet properties that are linked to say the left and the right layout constraints (e.g. var leftLayoutConstraint: NSLayoutConstraint). Then, you can set the constraint’s constant property as required when the cell is laid out, i.e. in the layoutSubviews function of the custom table view cell.
Non-selectability:
I am not sure what you mean by „I can simply not implement this“. Please make sure that you set the delegate property of the UITableView to the view controller where you want to handle cell selection. Selecting a cell changes the cells color by default, but you can change this: In the storyboard, select your table view’s prototype cell, and open Xcode’s utility pane (top rightmost button). Under „Table view cell“ you find „Selection“ that you can set to „None“.
I hope this helps!

View based NSTableView having Sluggish Scrolling

I am using View based NSTableView where I have around 30 columns and rows could be in between 200 - 1000. The problem is that the tableView is very sluggish. After doing some debugging, I figured out that adding an identifier to NSTableCellView made the scrolling super fast. But the problem arose that no data was displayed. Since all the data being displayed to the columns is using binding, so no code has been written for it. Now, I am not able to figure it out why is that happening or what is the correct way of using view based NSTableView using binding and reusing Cells. Could someone provide me some highlights on how to make the scrolling smooth for such scenarios.

Split View Controller showing only one view (Xcode 6)

I'm trying to get the split view controller working properly but apparently there's a bug in there or I'm missing something.
First of all, I've started a blank OSX Obj-C application, and in the Storyboard I've dragged the split view controller. Next, I've linked the segues from the main window controller to the split view and added two labels.
http://i.imgur.com/dlFObaF.png
When I build the project, it shows only the second page. Not to mention strange window size in the final build.
http://i.stack.imgur.com/IqRqr.png
I've tried everything.
This occurs in both vertical and horizontal split view.
Any suggestions?
I had the same issue myself today, but it's just the split line wasn't initiated properly.
To see, this, once you run your app, move your mouse toward the edge of the window and drag it, you will now see another view emerging.
To my best knowledge, I do not know how to fix this in IB or in code. Apparently NSSplitViewController does not have a property like UISplitViewControllerAutomaticDimension. Would appreciate if someone can contribute to this.
Edited: Found an answer via another thread. Basically, try to add some constraints to the subviews inside each view and that should prevent the size of a view to be zero. In my toy example, adding margin constraints to my buttons worked out well.

NSTableView redraw not updating display, selection sticking

Although I know of a solution to this problem, I am interested if someone can explain this solution to me. I also wanted to get this out there because I could not find any mention of this problem online, and it took me several hours over several days to track down. I have an NSTableView behaving strangely regarding redraws and its selection. The problem looks like this:
Table contents fades in, instead of appearing instantly upon it's appearance on screen. When scrolling through the contents, the newly appearing rows also fade in. When you make a selection (single or multiple), and scroll it off screen, then make another selection (that should replace, not add-to first selection), the first selection does not get cleared properly. If you scroll back to it, it is still there, in addition to your new selection. This is a display-update problem, not selection problem - i.e. your new selection is valid, it is just displayed wrong.
I tracked this through the NSArrayController I was binding to, the underlying Array, sorting, all the connections, and settings, etc., but all that has nothing to do with it.
What solved the problem was:
In the View Effects (right-most) Inspector, uncheck "Core Animation Layer" for the Window's main view.
Can anyone explain what is happening here, and perhaps improve upon the solution ?
It looks like Core Animation and NSTableView aren't getting along so well. The "fading" effect is a by-product of the way core animation works. When you have core animation in one view, it is also enabled in all of that view's subviews.
I don't recommend using core animation on the Mac unless absolutely necessary, because some interface elements (NSTextView and NSTableView, for example) aren't compatible with it. iOS has much better support for table views and such using core animation, mainly because it was designed with core animation in mind.
I know that some more simple UI elements are compatible (NSTextField and NSButton, for example).
If you absolutely need core animation in the rest of the window, put all the other views in a subview of the content view, while leaving the table view directly in the content view. You can then enable Core Animation in the other view.
Commenters, feel free to add to the list of what is and isn't compatible.

Creating a view with draggable text elements

I am trying to create a view for a kind of brainstorming application like, for example, OmniGraffle, with elements that contain textviews and can be dragged around. (Also, the should be connectable with arrows, but that is not (yet) the problem)
I did my homework and searched via google and read books about cocoa, but there seems to be no similar example around.
Since I am also new to cocoa, I’m a bit helpless here.
The thing I am sure of is, that I need a custom view in which I can create my elements - what I tried until now to do that is:
First, I searched for the syntax to add subwindows to a window to create my elements. Subwindows, I imagined, would automatically be movable and come to front and so on.
The problem: As the experienced Cocoa-programmers of you probably are not surprised, I was stunned to find nothing about anything like that - this seems to be something, that is just not intended in Cocoa?!
Then I thought about creating subviews that contain a custom view for the title bar drawing (where the user can click to drag the element) and a NSTextView.
Problems:
I read, that it is not so clever to create dozens of subviews in a window because that would be very slow (or would that be not so bad in this case because all the subviews would be instances of always the same class?).
Also I can’t find out how to load a subview from a nib- or xib-file. Would I need a viewController? Or would that make the dozens-of-instances-problem even worse?
And Apple tells you not to overlap subviews (okay, that would be not so important, but I really wonder how the guys at OmniGroup made OmniGraffle...)
Because of that, I now wanted to do the title-bar-drawing in the surrounding custom view and create the textview programmatically (as I understand, a text-“view“ ist not really a view and takes its functionality from NSCell to reduce all the effort with the views?).
Problems:
Even that failed because I was not able to create a textview that doesn’t fill the complete window (the initWithFrame: of the [[NSScrollView alloc] initWithFrame: aRect] just seems to be ignored or do I get that wrong?).
Also, there should be some buttons on each element in the final application. I imagine that would be easier to accomplish with a subview from a nib-file for each element?
Well, now that nothing works and the more I read, the more problems seem to occur, I am pretty confused and frustrated.
How could I realize such a program? Could someone please push me in the right direction?
I created a class for the draggable elements where I save position, size and text in instance variables. In my view, every new element instance is added to an array (for now, this works without a controller). The array is used to draw all the elements in a loop in drawRect:. For the text of the element I just use a NSTextFieldCell which is set to the saved text from every element in the same loop.
That way it is also possible to overlap the elements.

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