layout-manager

How to make an added JPanel visible inside a parent JPanel ? I am using Netbeans for designing my UI. I have a MainFrame.java , which contains two panels; namely headerPanel and bodyPanel . In headerPanel I have put three buttons,let it be button1 , button2 and button3 . Also I have created three separate files extending JPanel , name it panel1 , panel2 and panel3 . Then I added all my three panels inside bodypanel in MainFrame.java in constructor. bodyPanel.add(panel1); bodyPanel.add(panel2); bodyPanel.add(panel3); I want that on clicking the respective buttons only respective panels should

I have a jScrollPane and a button on a form. The button adds a component to the jScrollPane . I'm using a FlowLayout with a center alignment to arrange the components within the jScrollPane . The first component has no problems appearing and is aligned perfectly. When I then hit the button again, nothing seems too happen. When I follow the debugger it shows that everything happens precisely as before. The code that's being executed when the button is clicked: jScrollPane.getViewport().add(new Component()); This is how I setup the FlowLayout on the Viewport of the jScrollPane : jScrollPane

I need to position JFrame on my screen. But I can't make them appear on the right side of the screen bottom. Please can someone explain me how to position them, if you can describe how to do it, it would be great. Here is the code so far. //Gets the screen size and positions the frame left bottom of the screen GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment(); GraphicsDevice defaultScreen = ge.getDefaultScreenDevice(); Rectangle rect = defaultScreen.getDefaultConfiguration().getBounds(); int x = (int)rect.getMinX(); int y = (int)rect.getMaxY()- frame.getHeight(); frame

I read some posts here and I started why some people do @Override public Dimension getPreferredSize() { return new Dimension(500, 500); } instead of setPreferredSize(new Dimension(500, 500)); Isn't the second one better because it creates only one Dimension object whereas the first one possibly creates several (even if it's not that much wasted memory)? Or am I wrong? Is there a difference at all? A big difference is how the value can change over time, and so the one you choose should be dependent on what you're wanting to do with the code. If you simply call setPreferredSize(new Dimension(500

I have a JFrame, in this JFrame I have a JPanel that I draw on, this Panel can be any size and so I placed it into a JScrollpane to let me scroll when the panel is larger than the window screen size. Unfortunately does not work as I expected: Making the JFrame window smaller than the JPanel size does not show scroll bars The JScrollPane size now seems locked to the size of the JPanel I have added to it, where as before it resized to the bounds of it's JFrame window (it still kinda does this but only vertically now?!) The JPanel seems to assume the size of the JScrollpane regardless of what I

I have a panel derived from JPanel . I have a custom control derived from JLabel . I am attempting to center this custom JLabel on my panel. The only way I know to do this that will work is to use the a null layout ( setLayout(null) ) and then calculate the custom JLabel's setLocation() point so that it's in the right spot. The custom JLabel is physically moved from one panel to this panel in this app and I believe the location previously set in setLocation is affecting things. However when I set it to (0,0) the component goes up into the upper left corner. BorderLayout doesn't work because