JavaFX: bind to scrollpane width and height without bar sizes - java

I have a StackPane, which is inside a ScrollPane. I want that minimal size of StackPane was as the size of ScrollPane. This is my code
stackPane.minWidthProperty().bind(scrollPane.widthProperty());
stackPane.minHeightProperty().bind(scrollPane.heightProperty());
However, using this code the scroll bars (vertical and horizontal) are always visible and there is a small scrolling. I suppose that I include scroll bar size in minimal size of StackPane. How can I make StackPane minimal size be equal to ScrollPane and scroll bars are not visible if they are not needed?

Late Answer but maybe someone needs a solution.
All you need to do is to add a small offset like that:
stackPane.minWidthProperty().bind(scrollPane.widthProperty().subtract(20));
stackPane.minHeightProperty().bind(scrollPane.heightProperty().subtract(20));

Related

JPanel adjust to JScrollpane and children

I'm trying to make a ToDoManager in java. For now I have about what I want it to be for a basic version. But I'm having a problem with the size of a panel.
I have a main JFrame. This contains a JPanel, say jPanel1.
jPanel1 has 2 buttons (add and remove) and another JPanel (say jPanel2).
jPanel2 contains a JScrollPane, which contains a modified version of JTable.
The thing I want is to tell the JTable to stretch out, so i can view everything in the JTable, and then tell the JScrollPane and jPanel2 to "Pack", or resize, so the JTable is completely vissable (if not possible the JScrollPane should do its work and draw the scrollbars).
This is what I have got at the moment:
So maybe you can see 2 problems:
1) The horizontal scroll bar does not appear. (But I did set the scroll bar: HORIZONTAL_AS_NEEDED)
2) I did not set any preferred size for the main JFrame, nor for the jPanel1, but it packs always as the same size. So I would like to stretch the jPanel2 to the full JTable, and if that would exceed the screen size, draw the scroll bars.
Using another layout manager, it's a lot easier to comprehend the usage of the JPanels and this concludes the problem.

How to make JTextPane wrapped in JScrollPane shrink to fit the text

I have a JTextPane with HTML text.
I used GroupLayout (using WindowBuilder).
I've set the minimum size of my JFrame to 800x600 so the user cannot make it smaller than that.
The app has a big scrolling JPanel the size of the entire window. The top part of the panel is taken up by a JTextPane wrapped in JScrollPane. I have disabled the scroll bars and sized the JScrollPane to make the entire text visible.
In group layout the JScrollPane is set to stay constant vertically, but size horizontally.
My issue is that when the user makes the window larger the JScrollPane also expands, but now there is a big white space left at the bottom of the text pane. Is there a way that I can make JTextPane shrink to fit its contents.
Also if you suggest a different layout, I would be willing to try it.
I used this TextPanePerfectSize example from #camickr to solve a similar problem. The example uses validate() and pack() to adjust to the preferred size. You might be able to adapt it to your situation.
Take a look at SpringLayout. It gives you far more control over the positioning of components. Look at the SpringLayout tutorial if you get stuck.
The trick in your case is to bind the bottom (south) of your JScrollPane to the top (north) of the screen.

GWT - How to center contents inside ScrollPanel

I have a FormPanel inside a ScrollPanel. The ScrollPanel is located in the center part of DockLayoutPanel. I want to vertially and horizontally center the FormPanel inside the ScrollPanel. I tried a few ways to do this but no success.
I have tired putting a verticalPanel/horizontalPanel inside the scroll panel, and use it to wrap the formPanel. I set both scroll panel and horizontal panel to 100% width and height. However, the scroll panel is automatically resized according to the size of center part of DockLayoutPanel whereas the horizontal panel's size is always equals to the size of its child- form panel. So I cannot center the formpanel inside of horizontalPanel since their height and width are the same. I try to make the horizontalPanel's size be always the same as scrollPanel, but I have no idea how to do this. Setting horizontalPanel's size to 100% is not working.
So My question is this:
1.How do you center something in scrollPanel. I don't mind using css method if you know how to achieve this.
2.In my case above, is it possible to make the horizontalPanel to be always the same size as its parent container - scroll panel. If it is possible, my 1st question is solved then.
I had to center an image inside a horizontal scroll-panel. Sometimes I just have one image and sometimes there is a list of images to be centered and shown. I have fixed the size of the GWT image object and the width of the scroll panel.
I computed the scroll position inorder to center all the items and I used set scroll position (position can be -ve or +ve values).
When user scrolls the items then I would respect the user's decision and scroll them accordingly. However, if the user scrolls to extreme right of left, I would ensure that the scrolling positions are re-adjusted to scroll back to the boundary and not exceed it.
When the page is refreshed by scroll panel centres the items automatically.
In short, you need to center the items programmatically and by default the scroll panel would keep the items on one side (left and top).

How to set only the preferred width of Panel with flow layout?

I have a panel with flow layout, and it can contain a variable number of items - from 1 to 2000. I want to put it inside a scroll pane, scrollable in vertical direction, and with fixed width. The problem is, when I set preferred size of panel to something like (800,600), some items are missing, and there is no scroll. If I set up preferred size of scroll pane, then all elements in flow pane are put on one very long line.
Setting maximum size on any element seems to do nothing at all - layout managers ignore it.
How can I fix this?
I want to put it inside a scroll pane, scrollable in vertical direction, and with fixed width
You can use the Wrap Layout for this.
Don't set the preferred size of the panel. But you can set the preferred size of the scroll pane so the frame.pack() method will work.
You could use BoxLayout to do this:
JPanel verticalPane = new JPanel();
verticalPane.setLayout(new BoxLayout(verticalPane, BoxLayout.Y_AXIS));
JScrollPane pane = new JScrollPane(verticalPane);
//add what you want to verticalPane
verticalPane.add(new JButton("foo"));
verticalPane.add(new JButton("bar"));
This of course will use the preferred size of each component added. If you want to modify the preferred size for example of a JPanel, extend it and override getPreferredSize:
class MyPanel extends JPanel(){
public Dimension getPreferredSize(){
return new Dimension(100,100);
}
}
A note: BoxLayout will take in consideration getPreferredSize, other LayoutManager may not.
Please criticize my answer, I'm not sure it's completely correct and I'm curious to hear objections in order to know if I understood the problem.

How does a scroll pane do scrolling

In windows, Java, etc, the scroll pane scrolls the widgets inside. What I'm wondering is, how exactly does it do its scrolling? Does it change the location of each nested widget, or does it have a content widget that it moves around? Or is it something else? Also, when both scrollbars are present, how does it mask that little square at the bottom right? That square is sometimes used to resize. Is it a separate nested widget?
Thanks
I think it just changes the location of the widget, button, or thing-a-ma-bober.
But my second guess would be it just draws the components "outside" of the scroll pane without being seen and when you scroll it just redraws dynamically.

Categories