JavaFX Keep Drag and Drop Item Always On Top - drag-and-drop

I have a Pane object that holds several draggable objects. These objects are populated within the Pane from left to right and top to bottom and are all draggable. The problem comes when one of the items placed before others is dragged, it appears underneath those items that were populated after this one. I've included a small screen shot of this below. Here I'm attempting to drag "public", but it appears underneath the objects populated after it.
So, my question is, how do I keep the dragged object "always on top" of other draggable objects?

This is solved simply by using the ImageView's toFront() method.

Related

Depending of drag and drop operation from anchor position in unreal engine 4

I have the problem with Drag-and-Drop Operation for UI elements:
i have created a test object to drag: DragTestObject_BP and have override the functions:
OnMouseBottonDown Function and OnDragDetected.
Recepient will be HUD_BP with overridden is OnDrop function.
The problem is, that first drag-and-drop operation is functioning without problem only, if the anchor for drag object is set for upper left corner. Otherwise the drag object has some wired offset.
Position on start:
Drag object jumped by first mouse click on it
Might be a bit late, but youll want to put the widget you're clicking to drag ("DragTestObject_BP") inside of another widget.
It's probably a good idea to remove any canvas panel in "DragTestObject_BP" as well.
This will make the origin of "DragTestObject_BP" where it is located visually, instead of using the location of the canvas panel which is the issue you seem to have run into.

NSOutlineView disclosure triangle vertically off center

I'm working with an NSOutlineView on a macOS app and it provides disclosure triangles for items that can be expanded.
I'm also creating custom NSTableCellView items rather than using basic cell items. This allows me to create the cell how I want visually.
My issue is that when they're displayed, the disclosure triangle on the left is not centered vertically.
Notice how the disclosure triangles are not aligned properly. They're a bit lower than they should be. If you scroll away and come back, sometimes, they automatically align themselves correctly. Has anyone been able to fix this issue before?
For what it's worth, I'm using the following code as well for the cells.
self.outlineView.rowHeight = CGFloat(integerLiteral: 66)
self.outlineView.usesAutomaticRowHeights = true
It's hard to figure out what the problem is without seeing how you've set up your project, but I'm going to give it shot.
First, when usesAutomaticRowHeights is set to true, the outline view uses Auto Layout to position the cell views. Thus, you need to be utilizing constraints in your Storyboard or Nib file, or things will behave strangely (see: your picture). If I had to guess, the prototype cell view you set up in Interface Builder is having its autoresizingMask translated into Auto Layout constraints (which, generally, causes a boatload of problems).
What I would do is this:
Open up the Storyboard or Nib document containing the outline view.
Locate the prototype NSTableCellView instance that contains the street name text field in the Document Outline to the left of the canvas. (If you don't see the Document Outline, you can open it by clicking the item at Editor » Show Document Outline in the main menu).
Next, see if you have any constraints in place. If you do, remove them by selecting Editor » Resolve Auto Layout Issues » Clear Constraints under the menu item "section" that's titled All Views in ${YOUR_SCENE}.
Now, depending on what you're going for, there are different ways to go about setting up constraints, but here's what I would suggest. Assuming you want the street name to be centered vertically with the disclosure triangle, I would add a vertical constraint between the text field and its parent cell view like so:
With the text field selected in the Document Outline, click the Align icon in the lower right-hand corner of Interface Builder's main canvas area (see image).
In the popover that appears, check the checkbox next to Vertically in Container.
In the text field on the right side of the popover, enter a value of “0”.
Finally, click the “Add 1 Constraint” button.
You’ll probably see a red error (or yellow warning) sign show up, as the view has now opted into Auto Layout, but it only has a metric for its vertical position. So we now need to add some constraints to describe where the text field should be positioned on the x axis. Like before, we’ll define the constraints using the popover buttons on the lower right-hand side of the canvas:
Click the Add New Constraints button (the one to the right of the Align button).
On the diagram at the top of the popover, click the faint red lines on the left and right side of the white rectangle. This is telling Interface Builder we want to add leading and trailing constraints.
Now, enter the desired padding you want on each side of the text field. In the example image, I went with “4” points on both sides, but obviously, you can use whatever value(s) you think works best with your layout.
Finally, click the “Add 2 Constraints” button.
Any warning(s) that were present should now disappear, as we've added enough constraints to describe the position of the text field. In theory, you should now be able to build and run your project, and the text fields should be aligned with the disclosure triangles. With that said, there are plenty of other reasons a layout can get finicky, and considering usesAutomaticRowHeights is a new API in macOS High Sierra (and Steve Jobs is no longer there to beat it into Apple developers to make everything Just Work™), there could be issues that I'm unaware of.
Alternatively, you can set usesAutomaticRowHeights to false and have some object (e.g. a view controller, a NSObject subclass, etc.) conform to the NSOutlineViewDelegate protocol and implement the outlineView(_:heightOfRowByItem:) method to return any arbitrary height you want for different rows. The nice thing about sizing rows this way is that you can allow certain rows to be larger or smaller, depending on the role of the corresponding item. There are lots of tutorials on this, so I won't regurgitate a half-baked explanation here, but feel free to Google “Conforming to NSOutlineViewDelegate protocol” for more info.
Anyway, try the steps above, and see if they do anything for you, and if they don't, let me know. I can go as deep into the rabbit hole with you as you need, so just ask. Good luck!
For those like me who stumbled upon this issue many years later, here's the fix that worked for me, and requires a lot less work.
NSOutlineView has a function frameOfOutlineCell(atRow:) and the documentation states: You can override this method in a subclass to return a custom frame for the outline button cell
You can override the method in order to provide a frame that's actually in the vertical center of the row. And an important point that I learned from trial and error, is that you don't even need to provide that updated frame. Not sure if this is a bug or what, but for me, just calling super.frameOfOutlineCell(atRow: row) in the function override was enough to make the disclosure indicator appear in the correct location.
So my subclass of NSOutlineView is this:
class MyOutlineView: NSOutlineView {
override func frameOfOutlineCell(atRow row: Int) -> NSRect {
super.frameOfOutlineCell(atRow: row)
}
}
That's all. Hopefully that works for others as well!

Scroll to the dropped object when it's released outside of the current view of a GEF editor

I have a GEF editor with draggable figures. I have overriden the createChangeConstraintCommand of the main EditPart's XYLayoutEditPolicy.
This allows me to easily move (drag and drop) the figures.
The problem is, that if I drag one of them outside of the current view, although the scroll appears and the figure is moved, the view does not automatically scrolls to the dropped object.
Any idea how to implement this "auto-scroll" functionality? (It would be even nicer to have the "selected" (dragged/dropped) figure always visible in the view.)
Given the editpart object that has been dropped, you should use EditPartViewer#reveal(EditPart) method. Do this for example:
editpart.getViewer().reveal(editpart)

JavaFX 8, how to hide a pane in Splitpane?

I have a splitpane created from FXML that consists of Three panes left to right. I want to be able to hide the rightmost pane but I can't find anything to hide it. If I turn of the visibility it hides the pane content. What I want is to temporarily hide it, so the pane is removed visually.
As a temporary workaround I move the divider to 100%, but this leaves the divider visible. Another side-effect is that if I resize the main window the divider doesn't stay at the rightmost position.
Any tips on hiding one pane in splitpane?
Or any tips on the best way to achieve this without splitpane(rightmost pane needs to be resizable when not hidden). General pointers to techniques/containers would be appreciated since I'm new to Java/JavaFX but not to programming :)
Seems I've found it, even thought it's not a plain hide/show deal. My splitpane is named "mainSplitPane", and the one I want to hide/show is the third. Upon initialization of the controller I retrieve the third pane and store it in "componentsPane".
Declared in controllerclass:
Node componentsPane;
Called in initialize method of the controllerclass:
componentsPane=mainSplitPane.getItems().get(2);
Code to hide:
mainSplitPane.getItems().remove(componentsPane);
And code to show:
mainSplitPane.getItems().add(2, componentsPane);
mainSplitPane.setDividerPosition(1, 0.8);
A side effect is that I have to set dividerposition since it's removed.

XCode 4 Interface Builder: A better way to work with lots of overlapping views

In IB I have quite a few views that are shown. Many of them are hidden when the app loads, but are shown later when buttons are pressed. This is all fine, but when building this layout in IB it is extremely difficult to layout anything because there are so many overlapping views, some of which are partially transparent (ones that are set to hidden) and other are completely overlapping and covering others. This makes layout very hard.
What is the best method when laying out lots of views like this? Is there another way to break things up? Or better yet, can I hide a a view completely (like in photoshop) so that I can edit the ones underneath, then turn that layer back on?
Another option when trying to select a view that is obscured by another is the shortcut:
'ctrl' + 'shift' and click
It displays a list of all the views under the cursor.
I'm not aware of any way to hide objects in the canvas, but a useful trick for complex layouts is to double-click an item in the document tree to the left - this selects the item and puts focus on the canvas, you can the use the cursor keys to nudge it about.
This doesnt solve the problem of not being able to see things because there are, for example, five or six labels occupying the same space, but if that is the situation it may be a better idea to have a single label and change its contents in code.
I ran into this issue for an app I'm building that has an arial-view image of a park with clickable hotspots. When a hotspot is clicked a popup UIview is displayed with information about that spot in the park. I use the same VC/XIB for three parks. This makes the XIB really busy and hard to work with (i.e the same issue that you have) The detail UIViews make it hard to work with the views underneath. My workaround was to pick each detailed UIView that was hiding the part of the XIB I wanted to work on, and add 1000 to the UIView origin.x in the size inspector. This moved those UIViews enough out of the way for me to do what I needed to with the XIB. Then when I was done, I moved them back by x 1000. (I just needed to move them out horizontally to do what I needed to)
I know its clunky but given that XCode does not have a convenient way to hide portions of an XIB - it was the quickest approach I could think of!
One approach to handling overlapping items in IB is:
Ensure the groups of items that you want to hide are grouped into Views.
Give these Views names: e.g. ViewOptionA, ViewOptionB and ViewOptionC.
Can do this by clicking on name of view in the tree while it is selected and then typing new name.
When you want to hide one of those groups of items:
a) Select the View by either:
i) Clicking on it in the tree at the left or
ii) Ctrl-Shift Clicking in the layout editor and then select the view from the list.
b) In the Attributes Inspector set Alpha to 0.
When you want to unhide one of those groups of items:
As for 2) but set Alpha back to 1
[You do need to remember to unhide all views before you publish!
If you are forgetful like me then perhaps you could subclass UIView and set Alpha to 1. I haven't tried this subclassing idea yet.]