I'm trying to implement a sort of drag functionality into my app. As a simplistic example imagine I have a 2x2 square of buttons, so four buttons total. Clicking a button will perform some other functionality however I want when they hold and drag one of these buttons for it to do something else (ideally if you drag one button and drop it while in the space of another button the two buttons will swap places, as long as I can get dragging and dropping working the swap should be easy).
I've done some research and followed a few tutorials but seemed to get errors at one step or another with all of those. It seems ListViews and GridViews have some drag and drop functionality in them already , but I had trouble properly arranging my buttons (there are many more than four and they are in very specific positions, like a diagram) inside these views, let alone getting drag and drop working with them.
How would I go about doing this? Ideally I could just tag these buttons as draggable, and then on a drag-drop event check for a drop position, then if the position is valid perform a swap method. I just can't seem to figure out how to make them draggable or how to have an event that checks a drop position.
Thanks.
Easy peasy, create a custom control that looks the way you want it to, set ManipulationMode to TranslateX|TranslateY, handle manipulation delta events to update positioning with something like a Canvas or TranslateTransform and when manipulation completes - either make it click or animate to the new position. From my experience - getting any other manipulations to work with a regular Button class just isn't working and since a button is a really simple control - it is easier to create your own than try to extend the existing one in such cases.
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This question already has an answer here:
NSTableView with +/- buttons like in System Preferences using only Interface Builder
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I'm building an OSX app and want to create a set of controls similar to what's found at bottom of the standard Network Preferences configuration panel. I'm running into some layout problems that I wouldn't have expected.
These are my specific questions:
What contains the 3 buttons so there's similar shading all they way across the row where the buttons are positioned? In particular, what's causing the area without buttons to have shading?
How do you do this without getting a double border where the row of buttons meets up with the table?
I want to do this with an xib file. This may be incredibly simple, but I'm missing something I guess.
I find that if you make a button with style "Gradient" and type "Momentary Change", then it looks like the other buttons but does not respond to clicks, so you can use that as the area after the last button. (The NSMomentaryChangeButton is documented as changing the image and title when clicked, so if you don't use an image or title, nothing should change.)
If you check Refuses First Responder in the attributes inspector, then it will not be possible to highlight this blank button using Full Keyboard Access.
Ken Thomases also brings up the issue of the blank button being shown as a button to Accessibility. One can fix that by using a subclass of NSButtonCell that has just one method:
- (BOOL)accessibilityIsIgnored
{
return YES;
}
I think that's easier than writing a custom view.
As d00dle says, avoid double borders by slightly overlapping things.
Since you want the slack space to have the same background as the buttons, and since the buttons can change appearance from release to release of the OS, the best thing to do is to get the frameworks to draw it like it would the buttons.
Rather than using an actual button as JWWalker suggests, I have used a custom view that leverages NSButtonCell to draw the background. The advantage is that you can be sure there's no chance of getting undesirable behavior. For example, a button could get focus (for users who have All Controls selected in System Preferences > Keyboard > Shortcuts > Full Keyboard Access) so that the user could Tab to it. Accessibility will report the presence of the button through VoiceOver. Etc.
Configure the button cell just like the buttons (set buttonType and bezelStyle). In the view's -drawRect: call [buttonCell drawWithFrame:rect inView:self];, where rect is similar to the frames of the buttons. Since one way to avoid double borders is to make the buttons larger than the view's bounds, you may need to do the same for rect. For example, you might want to use NSInsetRect(self.bounds, -1, -1).
The buttons are buttons... This can be accomplished with a custom view drawing border and the background "shading".
To avoid the double border where the table and the custom view meet you simply align it so they overlap by 1 point (pixel) or avoid drawing the top border in your custom view.
I don't know of any standard object capable of doing this.
I just have it in my mind. And I can't explain it so here it goes.
A system that only uses 1 form?
It have a two panel, left and right.
The left is consist of buttons
Then the right is associated on the buttons and will change whether what button will be clicked.
Any ideas?
My preference is to do this via custom controls, rather than panels... but panels can work too.
There are a number of ways to do this:
Keep all of the controls layered on top of each other, and then set the Visible property to false for controls/panels you don't care about and to true for the Control/Panel that you do
Move the controls you don't care about out of the visible area
Remove/Add the Controls/Panels from Form's controls collection entirely
I think you can also get a TabControl to put the tabs along the left side, with some formatting that looks more like buttons, such that what you want will be handled without needing to write any code to switch layouts
Any of those can work. Whichever option you use, I have two recommendation for controlling layout and making the transitions smooth.
Call SuspendLayout() before making any changes, and then call ResumeLayout() when you're done. This will help avoid stuttering or a partially rendered form.
Look at the TableLayoutPanel Control. This control will allow you to arrange your top-level panels so that they can be resized with proportion. If you also then dock your individual panels, you can quickly build your program so that it resizes correctly.
You can have several panels, one on top of another. Change their visibility, depending on which one you need at a given moment.
Option #2 would be using a vertical tab control (or a tab strip - see another answer there).
I have two buttons that I want to be kept the same size, but the problem is that they have two different parent views. Autolayout seems to be ignoring the "equal size" constraint in this scenario. Constraining buttons with the same parent view works just fine.
I've created a very simple example that depicts what I am seeing:
As you can see from the above, buttons Two and Three are both set to have the same size constraint as button One. The only difference is that button Three is contained within another NSView. There are no width constraints that are linking button Three and its containing view.
However, when I run and resize the window, it looks like:
It doesn't matter whether I use the Interface Builder layout, or do it in code using the -[NSLayoutConstraint constraintWithItem:attribute:relatedBy:toItem:attribute:multiplier:constant:] method.
What am I missing? Is this not supported by Autolayout? Thanks a lot.
Edited: Added screenshot to indicate button Three's constraints.
This should work OK. I set up an example project to do the same thing. I have three buttons with equal width constraints between button one and button two. Then the same between button two and button three. Button one has a trailing edge constraint relative to it's parent view.
Note that between the second and third button, Interface Builder didn't let me do this in the main window. Instead, I had to do it using the document list on the left.
The result can be seen below:
Here's the link to the project:
https://github.com/MaxMacleod/ThreeButtonConstraintTest1
Couple of caveats. First, this is an iOS rather than an OS X project (I'm an iOS guy!). However the principles should be the same. Secondly, this doesn't pinpoint the exact reason why your project isn't working. However, if you can compare what this sample project does against yours, we can figure it out. I'll then update this answer. Better still if you could make your project available, I'd be happy to take a look.
Can I drag an item (image, rectangle or other shapes ...) and drop it freely somewhere on the screen? I know there is a way to drag and drop items from a GridView to another, but I would like to do it without restrictions (and without Directx).
And I also found only a quickguide for drag&drop, no useful examples, that's why I'm curious.
I had the same problem. After trying to work with Manipulation etc I just gave up and implemented a quick work around.
I just placed my item ( Circle in my case ) into a ListView and allowed the ListViewItems to be dragged. (CanDragItems). I also removed all the styles so it wouldn't look like a ListView.
This way I could drag my ListViewItem (which was just a circle) and drop it somewhere. You don't have to drop it into another ListView.
If you put these property
Drop="imgCart_Drop_1" AllowDrop="True"
on an image for example then you can capture the drop event.
I hope this helps
I have seen that in Cocoa I can create a custom view using drawing primitives which allows me to draw what I like but at a very low level.
Instead I'd like to create custom widgets using a combination of existing controls. For example:
I'd like to create a table with images and combobox in cells
I'd like to create a custom widget wich is a combination of several (for example a list, a button and combobox)
How can I approach this problem ?
Secondly a typical cocoa developer uses external controls? Is there a repository or a list of interesting external custom controls (commercial or free) ?
I'd like to create a table with images and combobox in cells
There already exists NSImageCell and NSComboBoxCell. Are you sure you need to do anything different?
If the problem is that you want an image and a combo box in the same cell, you will have to subclass NSCell. Currently table views can only contain cells, not views, which makes your life harder (as understanding how cell drawing works is more difficult). That will change in Lion, however, so if you can wait until then, this will become easier!
I'd like to create a custom widget wich is a combination of several (for example a list, a button and combobox)
How is your custom widget different to just placing those three things in the same view?
You could write your own NSView subclass. When it's created, it should create a list, a button and a combobox and add them as subviews to itself. Your NSView subclass should handle the logic of keeping them in sync or doing whatever it is you want them to do. Then, to use this combination control in Interface Builder, you place a Custom View and set its class (rightmost tab of the inspector) to your NSView subclass.
BTW, on a tangent, are you sure you mean combobox? Loads of people coming from Windows get this one wrong. A combobox is a combination of a menu and a text field: it allows the user to enter custom text that is not in the menu. If you just want a dropdown menu of choices (and the user can't enter a custom one), you use an NSPopupButton.
Secondly a typical cocoa developer uses external controls?
Yes, sometimes. Things like BWToolkit can be very useful. There's a lot more that are just floating around mailing lists as code snippets, rather than being cleaned up and put in a library. Search for what you need to do!