I was learning javafx and came across these two statements which I don't know their difference.
Pane pane = new Pane();
and
StackPane pane = new StackPane();
Can somebody enlighten me about the difference and when to use which?
Both are layouts but the Pane is the basis of all the other layouts, the difference is that the Pane offers a free positioning of nodes, and The StackPane (and other Node with the suffix Pane called Built-in Layout) in return, follow their own logic (Positions/Constraints...). The 'StackPane' for example lays out its children in a back-to-front stack StackPane. This is only superficial and limited information, here's a good tutorial : Layout in JavaFX
The difference between both layouts is positioning of the children and the resizing of resizeable children.
Pane does not do any positioning. The child's layoutX and layoutY are left unmodified. Furthermore resizeable children are resized to their preferred sizes.
StackPane determines the position of children based on the alignment set for the child itself or the one set for the StackPane itself, if no position is set for the child. Resizable children are resized to a size that fits the StackPane's size best (still taking into account max size). Both can be modified by a margin set for individual children...
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Suppose you have a block of code:
Pane pane = new Pane();
pane.getChildren().add(circle);
pane.getChildren().add(rectangle);
Scene scene = new Scene(pane, 400, 400);
Do you have to write pane.getChildren().add(===); every time you want to add something to the pane? Similarly, what is the difference in just writing ..
Pane pane = new Pane(circle, rectangle);
Scene scene = new Scene(pane, 400, 400);
As I have found that it does the exact same thing when I run the program and have the shapes display. Additionally, what is the different in writing with the use of Pane instead of:
Group root = new Group(circle, rectangle);
Scene scene = new Scene(root, 400, 400);
Any help would be greatly appreciated! I have been looking online and have not seemed to have found anything that truly answers all of my questions.
There's not really any difference between:
Pane pane = new Pane(node1, node2);
And:
Pane pane = new Pane();
pane.getChildren().add(node1);
pane.getChildren().add(node2);
Both approaches add the nodes the the children list of the layout. It's just that the first approach does this via the constructor; it's basically a shortcut for the second approach. However, the second approach can be used at any time so long as you have a reference to the layout.
Here are some differences between Pane and Group, though I can't promise this is an exhaustive list:
A Group will take into account any transforms or effects on its children when computing its layout bounds. This can have a profound affect on how your UI behaves when nodes are transformed (or have an effect applied on them). For instance, when you rotate a square the width and height grows and shrinks over time. If that square was in a Group then the Group's width and height would correspondingly grow and shrink; a Pane would not do this.
The Group class extends directly from Parent. The Pane class extends from Region (and Region extends from Parent). That means a Group has none of the styling options provided by Region (e.g. backgrounds, borders, etc.).
The Javadoc of Group also says:
Any transform, effect, or state applied to a Group will be applied to all children of that group.
I've never really experimented with this, so I'm not sure if this is truly different behavior than Pane.
Also, keep in mind that you'll typically want to use Pane or, more specifically, subclasses of Pane. This includes layouts such as BorderPane, VBox, and StackPane. Those layouts automatically manage their children to resize and position them according to the layout's rules. You can use nested layouts to achieve more complex designs. Personally, I've really only used Group if I want the behavior mentioned in point one above or if I'm using 3D shapes.
I have created TreeTableView by coding. Then I created 2 fxml files. one(overview.fxml) has splitpane(left side is label andand button and right side nothing) and the other(RootLayout.fxml) one with a menu bar which wraps the first one. How can i set bind my treetable view which is in main class to the right side of splitpane?
try this sorry for the earlier blunder
SplitPane sp = FXMLLoader.load(getClass().getResource("/overview.fxml"));
StackPane container = new StackPane();
container.getChildren().add(YourCreatedTreeViewNode);
sp.getItems().add(container);
sp.setDividerPositions(0.3f, 0.6f, 0.9f); // you can tweak it any how
SplitPane two or more sides, each separated by a divider, which can be dragged by the user to give more space to one of the sides, resulting in the other side shrinking by an equal amount. Nodes needs to be placed inside a layout container before they are added into the SplitPane. If the node is not inside a layout container the maximum and minimum position of the divider will be the maximum and minimum size of the content.
Safe to say you just add your nodes to the SplitPane and it will do the positioning..
hope it helps
I have this ScrollPane which I holds many components. I want to use the ScrollPane into many components with different size.
I solved temporary the problem using Rectangle2D
Rectangle2D primaryScreenBoundsthree = Screen.getPrimary().getVisualBounds();
But this is not working properly when I insert the ScrollPane with different components. I also tested this:
scrollthree.setPrefSize(ScrollPane.USE_PREF_SIZE, ScrollPane.USE_PREF_SIZE);
But again the result is not appropriate:
How I can fir the ScrollPane into the parent components borders?
Screen.getPrimary().getVisualBounds();
This returns you the bound of the Screen(Monitor) which you are using.
Bounds is the width and height of the Screen !
Inorder to use scrollPane to fit into your parent, don't use scrollthree.setPrefSize. You don't have to specify the size of the scrollPane, it will automatically fit into Parent
Infact, all the javafx panes fit into their respective parents !
I'm using StackPanel as container for my figures, panels, etc. What I discovered, that coordinates X,Y (0,0) are placed right in center of my panel.
Is it possible to move it to left top od Pane ?
Calculating all dimensions from center is much more difficult.
You can set the layout of Nodes added to the StackPane to a position within the Stackpane using the StackPane.setAlignment(node, position) method:
Label topLeftLabel = new Label("Top Left");
StackPane stack = new StackPane();
stack.getChildren().add(topLeftLabel);
StackPane.setAlignment(topLeftLabel, Pos.TOP_LEFT);
Even though this is possible, from your brief description of how you are trying to use the StackPane, it sounds like you would be better off using a regular Pane, or a Group or an AnchorPane for the kind of absolute positioning you appear to be wanting to achieve.
Possibly look into using a visual tool such as SceneBuilder as well. Even if you don't end up using the FXML it outputs, SceneBuilder should give you a much better idea of how JavaFX layout mechanisms work. SceneBuilder makes use of AnchorPane as its default layout pane used to provide absolute positioning for elements (which seems to be what you want to achieve).
The previous answer is of course the best in this situation, but it is also wise to know that you can move Nodes on the StackPane using Translation.
Ex.
Label topLeftLabel = new Label("Top Left");
StackPane stack = new StackPane();
stack.getChildren().add(topLeftLabel);
topLeftLabel.setTranslateX(stack.getWidth()/2);
topLeftLabel.setTranslateY(stack.getHeight()/2);
It would do the same thing (but may look a bit worse)
I have a problem in flex scroll bars. I have a mxml component based on canvas. Inside that I have used a VBox for my form. Above that Vbox I have another canvas just for title.
My form gets longer than normal screen size when the grid inside that is filled with more data. In that case I want a vertical scroll bar just for Vbox in which my form is located. But the whole canvas is getting scrollbar including title canvas. how to solve this problem.
I set vertical scrollbar policy of main canvas to off and inside Vbox's VerticalScrollbarPolicy to on. but that's not working. It is not overriding the property of parent container.
Thanks.
Keep your Form inside a Canvas inside the parent canvas instead of VBox. VBox and HBox are set to grow automatically in the parent container, so if your form grows, your corresponding VBox will grow as well.
You want to overload the "updateDisplayList" function for your parent canvas, and force the height of your form Vbox to be canvasHeight-titleHeight (including padding, space, etc...) so that the VBox never grows larger than the screen. This will solve your problem. Just make sure you check for the existence of the VBox as sometimes the updateDisplayList will be called before it has been instantiated.
Had the same problem myself and decided to take the easy route.
Have the following
App->vbox->[vbox + hbox]
components are dynamically being added to last vbox. Wanted hbox to stay on screen and have scrollbars only in vbox above it(2nd vbox).
Was experiencing the same problem. All containers had scroll policy=off except for last vbox, but when dynamically adding components, when the components filled the vbox > 100%, the outer vbox would start to scroll.
Resolution was simple once I went back to the documentation.
Set scroll policy - horizontal and vert on app and first vbox to off, and also added autoLayout=false. This causes the engine to not resize the components after initialization, ie, they are static sized.
Once I added this property, no more scrollbars except for the inner vbox.
Tada!