So, I have this JTexrtArea which is almost perfect for my needs. The only thing wrong with it is the line spacing. I can't set it. (Why not JTextPane? Because spacing CAN be changed in JTextArea and JTextArea is way lighter thatn JTextPane, and I have a bunch of those in my program).
I have asked this question before, and this is the answer that I got from user StanislavL:
To override JTextArea's line spacing take a look at the PlainView (used to render PLainDocument).
There are following lines in the public void paint(Graphics g, Shape a) method
drawLine(line, g, x, y);
y += fontHeight;
So you can adapt the rendering fixing y offset.
In the BasicTextAreaUI method to create view. Replace it with your own implementation of the PlainView
public View create(Element elem) {
Document doc = elem.getDocument();
Object i18nFlag = doc.getProperty("i18n"/*AbstractDocument.I18NProperty*/);
if ((i18nFlag != null) && i18nFlag.equals(Boolean.TRUE)) {
// build a view that support bidi
return createI18N(elem);
} else {
JTextComponent c = getComponent();
if (c instanceof JTextArea) {
JTextArea area = (JTextArea) c;
View v;
if (area.getLineWrap()) {
v = new WrappedPlainView(elem, area.getWrapStyleWord());
} else {
v = new PlainView(elem);
}
return v;
}
}
return null;
}
I grasp the general idea of what he's telling me to do, but I don't know how to do it.
Also, I wouldn't like to override the default JTextArea "property", I'd like to have a choice - to use the default one or to use a custom one.
Only change in JTextArea code would be from
y += fontHeight,
to
y+= (fontHeight +(or -) additionalSpacing).
How do I achieve this?
Which classes do I use/copy?
Where do I put them?
How do I make them usable?
How do I get the whole thing working?
If you think this is too specific to be useful, maybe someone could write a general tutorial on how to create a custom swing component based 100% on an existing one. Then someone could easely change some values to better adjust it to it's needs.
I am simply going to copy-paste my answer from your other question.
I'd like to change the spacing inbetweem the rows of a JTextArea
My first thought was that overriding javax.swing.JTextArea#getRowHeight would be sufficient. The javadoc clearly states
Defines the meaning of the height of a row. This defaults to the height of the font.
So I was hoping that by overriding this method, you would adjust the definition and you would get more spacing between the rows. Bummer, didn't work. A quick search on the usages of that method in the JDK revealed the same. It is mainly used to calculate some sizes, but certainly not used when painting text inside the component.
By looking at the source code of the javax.swing.text.PlainView#paint method, I saw that the FontMetrics are used, and those you can easily override in the JTextArea. So second approach was to extend the JTextArea (bwah, extending Swing components but it is for a proof-of-concept)
private static class JTextAreaWithExtendedRowHeight extends JTextArea{
private JTextAreaWithExtendedRowHeight( int rows, int columns ) {
super( rows, columns );
}
#Override
public FontMetrics getFontMetrics( Font font ) {
FontMetrics fontMetrics = super.getFontMetrics( font );
return new FontMetricsWrapper( font, fontMetrics );
}
}
The FontMetricsWrapper class basically delegates everything, except the getHeight method. In that method I added 10 to the result of the delegate
#Override
public int getHeight() {
//use +10 to make the difference obvious
return delegate.getHeight() + 10;
}
And this results in more row spacing (and a caret which is way too long, but that can probably be adjusted).
A little screenshot to illustrate this (not as nice as some of the other ones, but it shows that this approach might work):
Small disclaimer: this feels like an ugly hack and might result in unexpected issues. I do hope somebody comes with a better solution.
I personally prefer the solution StanislavL is proposing, but this gives you an alternative
That's a piece of code. It's not finished. Line spacing between wrapped lines is not implemented. You can get full source of WrappedPlainView or PlainView and add your code there to achieve desired line spacing
import javax.swing.*;
import javax.swing.plaf.basic.BasicTextAreaUI;
import javax.swing.text.*;
public class LineSpacingTextArea {
public static void main(String[] args) {
JTextArea ta=new JTextArea();
JFrame fr=new JFrame("Custom line spacing in JTextArea");
fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ta.setText("Line 1\nLine 2\nLong text to show how line spacing works");
ta.setLineWrap(true);
ta.setWrapStyleWord(true);
ta.setUI(new CustomTextAreaUI());
fr.add(new JScrollPane(ta));
fr.setSize(100,200);
fr.setLocationRelativeTo(null);
fr.setVisible(true);
}
static class CustomTextAreaUI extends BasicTextAreaUI {
public View create(Element elem) {
Document doc = elem.getDocument();
Object i18nFlag = doc.getProperty("i18n"/*AbstractDocument.I18NProperty*/);
if ((i18nFlag != null) && i18nFlag.equals(Boolean.TRUE)) {
// build a view that support bidi
return super.create(elem);
} else {
JTextComponent c = getComponent();
if (c instanceof JTextArea) {
JTextArea area = (JTextArea) c;
View v;
if (area.getLineWrap()) {
v = new CustomWrappedPlainView(elem, area.getWrapStyleWord());
} else {
v = new PlainView(elem);
}
return v;
}
}
return null;
}
}
static class CustomWrappedPlainView extends WrappedPlainView {
public CustomWrappedPlainView(Element elem, boolean wordWrap) {
super(elem, wordWrap);
}
protected void layoutMajorAxis(int targetSpan, int axis, int[] offsets, int[] spans) {
super.layoutMajorAxis(targetSpan, axis, offsets, spans);
int ls=spans[0];
for (int i=0; i<offsets.length; i++) {
offsets[i]+=i*ls;
}
}
}
}
Related
I'm trying to find a way to change the line spacing in a JTextArea component.
A little bit of searching always seems to reveal the same answer: "Use a JTextPane instead and then call setParagraphAttributes".
But I'm wondering whether it's possible to achieve this with just a JTextArea by, for example, messing with the font.
With the deriveFont(...) method, it's possible to change the tracking and the kerning of the font, i.e. the horizontal spacing between characters, but I haven't been able to find a way to change the vertical spacing (maybe ascent, descent, leading). Am I missing something there?
As camickr pointed out, JTextArea does not provide a way to change the line height directly. It simply uses the font height provided by the corresponding FontMetrics.
But, this leaves a point of attack open using the following helper-class:
public class FontMetricsWrapper extends FontMetrics {
private final FontMetrics target;
public FontMetricsWrapper(FontMetrics target) {
super(target.getFont());
this.target = target;
}
#Override
public int bytesWidth(byte[] data, int off, int len) {
return target.bytesWidth(data, off, len);
}
#Override
public int charWidth(char ch) {
return target.charWidth(ch);
}
#Override
public int charWidth(int codePoint) {
return target.charWidth(codePoint);
}
// ... tons more #Override's, all of the same form:
//
// #Override
// public baz foo(bar, ...) {
// return target.foo(bar, ...);
// }
}
Then, it becomes possible to create the JTextArea like this:
JTextArea myTextArea = new JTextArea("Some text") {
#Override
public FontMetrics getFontMetrics(Font font) {
return new FontMetricsWrapper(super.getFontMetrics(font)) {
#Override
public int getHeight() {
return 10; // Gives line height in pixels
}
};
}
};
This is definitely not the cleanest solution and is merely meant as proof of concept. For example, one issue is that getFontMetrics(...) is called quite often, and, in the given example, creates a new instance of the wrapper class each time. So, at the very least, a HashMap that caches the created FontMetricsWrapper for each given font would be in order...
But, what I was really hoping for was a way to play with the Font or maybe the associated FontRenderContext passed into the JTextArea to modify the line height. For example, is there some way to influence font's reported ascent, descent, and leading values? Seems strange that you can change pretty much any other aspect of the font's appearance, except this one...
What's wrong with light-weight coding?
Nothing, you should use the simplest component for the job. But if the simple component doesn't support a requirement it is usually because the requirement is more complex and you need a more complex component to implement the functionality. Rarely would it be as simple at setting a property of a class.
Sometimes I'm simply interested in learning something new and figuring out what's possible.
Swing text components use a View to paint the text. It is the view's responsibility to format and position the text. So each view determines when to wrap and where to position the next line.
In the case of a JTextArea it uses either a Plainview or a WrappedPlanView. For the Plainview the painting code is:
drawLine(line, g, x, y);
y += fontHeight;
where the fontHeight is determined by using the FontMetrics.getHeight() method.
So the value is basically hard coded in the View. You could always provide a custom View for your text area, but overriding a View is generally not an easy task.
I have tp place a AutoCompleteField in one of my screen in Blackberry app. I have to show a place holder text to provide hint for user to enter the information.
Here is the below code of AutoCompleteField
BasicFilteredList filterList = new BasicFilteredList();
String[] address = { "T 115 Centro Galleria Shopping Centre, Cnr Old Collier and Walters Road Morley WA 1522",
"1423 SEAVIEW POINT POINT COOK VIC 2674",
"Lot 1498 Yarraman Road Wyndham Vale VIC 3795",
"Lot 3506 Witchmount Close Hillside VIC 4055",
"6 Paas Place Williamstown VIC 4233",
"Lot 99 14 James Close Sunbury VIC 4502",
"1 Charlotte Street Clayton South VIC 4779" };
filterList.addDataSet(1, address, "address", BasicFilteredList.COMPARISON_IGNORE_CASE);
AutoCompleteField autoCompleteField = new AutoCompleteField(filterList){
public void onSelect(Object selection, int SELECT_TRACKWHEEL_CLICK) {
ListField _list = getListField();
if (_list.getSelectedIndex() > -1) {
if(selectedText!=null){
BasicFilteredListResult result = (BasicFilteredListResult) selection;
selectedText.setText(result._object.toString());
}
}
}
};
add(autoCompleteField);
Anyone, please suggest me how could I implement the same.
Thanks.
You can use a similar technique to the one shown here for normal EditFields. Basically, you need to override the paint() method in an AutoCompleteField subclass. In paint(), you check and see if the field is empty, and if so, you manually draw the placeholder text you want.
The difference is that AutoCompleteField is a Manager with a BasicEditField inside of it. So, to draw the text properly, you need to figure out the x and y offsets of the edit field within the parent Manager (the AutoCompleteField).
So, replace your AutoCompleteField instance with an instance of this class:
private class CustomAutoCompleteField extends AutoCompleteField {
private int yOffset = 0;
private int xOffset = 0;
public CustomAutoCompleteField(BasicFilteredList filteredList) {
super(filteredList);
}
protected void paint(Graphics g) {
super.paint(g);
if (xOffset == 0) {
// initialize text offsets once
xOffset = getEditField().getContentLeft();
yOffset = getEditField().getContentTop();
}
String text = getEditField().getText();
if (text == null || text.length() == 0) {
int oldColor = g.getColor();
g.setColor(Color.GRAY);
g.drawText("enter text", xOffset, yOffset);
g.setColor(oldColor);
}
}
public void onSelect(Object selection, int SELECT_TRACKWHEEL_CLICK) {
ListField _list = getListField();
if (_list.getSelectedIndex() > -1) {
if(selectedText!=null){
BasicFilteredListResult result = (BasicFilteredListResult) selection;
selectedText.setText(result._object.toString());
}
}
}
}
I tested this on OS 5.0, with an instance that didn't have any margin or padding set. It's possible that with different layouts, you may need to adjust the logic for calculating the x and y offsets. But, the above code shows you the basic idea. Good luck.
Edit: the above code is presented with the caveat that your onSelect() method is clearly relying on code not shown. As is, the above code won't compile. I left onSelect() in there just to show that I'm essentially just replacing the anonymous class you originally had, and not doing anything different in your onSelect() method, as it's not directly related to the placeholder text issue.
I made some menu and it is to update conmmon variables (for text on grid) then the out-of-focus dialog must repaint the grid. Here is the screenshot:
The main control panel is always at top position and 'Data Display' panel is always sitting behind it. When press a button on front panel, Data Display must update its grid. Currently, the common variable 0.4 on the grid is updated by adding listener and works fine. But the grid itself is not repainting anymore. How can I repaint the out-of-focus dialog in real time?
Here is the code of the front panel:
public class MainDisplayForm extends javax.swing.JFrame {
Storage st = new Storage();
DisplayForm dF = new DisplayForm();
....
public MainDisplayForm() {
initComponents();
Btn_IncreaseGain.addActionListener(new ButtonListener_IncreaseGain());
}
....
} //MainDisplayForm ends here.
class ButtonListener_IncreaseGain implements ActionListener {
DisplayForm dF = new DisplayForm();
Storage st = new Storage();
ButtonListener_IncreaseGain()
{
}
public void actionPerformed(ActionEvent e) {
st.iGain = 20;
dF.revalidate();
dF.repaint();
System.out.println("Testing");
}
}//Listener ends here.
Here is code of Data Display:
public void paint(Graphics g)
{
g2 = (Graphics2D) g;
paintComponents(g2);
//added numbers are for adjustment.
int x = this.jPanel1.getX()+8;
int y = this.jPanel1.getY()+30;
int width = this.jPanel1.getWidth()+19;
int height = this.jPanel1.getHeight()+40;
//labelling voltages
label0.setText(st.zero);
label1.setText(st.v1);
label2.setText(st.v2);
label3.setText(st.v3);
label4.setText(st.v4);
label5.setText(st.v3);
label6.setText(st.v4);
g2.setColor(Color.darkGray);
for(int i=x; i<width; i=i+80)
{
g2.drawLine(i, y, i, height);
}
int j = 0;
for(int i=y; i<height; i=i+80)
{
j++;
//st.iGain
g2.setColor(Color.orange);
if(j==1)
{
double k1 = st.iGain * 0.4;
st.v1 = Double.toString(k1);
g2.drawString(st.v1, x+5, y+10);
}
if(j==2)
{
double k2 = st.iGain * 0.3;
st.v2 = Double.toString(k2);
g2.drawString(st.v2, x+5, y+90);
}
g2.setColor(Color.DARK_GRAY);
g2.drawLine(x, i, width, i);
....
} //grid info is not completed yet.
Thanks,
Focus isn't the issue and has nothing to do with your current problem. The solution is to change the properties of the data grid by updating fields it contains via setter methods and calling repaint on the JComponent (perhaps a JPanel, or some other component that derives ultimately from JComponent) held by the data grid. The paintComponent method of this component should use its class fields to update what it draws.
You almost never paint in the paint method of a JComponent and certainly you don't want to draw directly into a top-level window. You also probably don't want to set text of JLabels, JTextFields, or any other JTextComponent. from within paint/paintComponent.
I can't see why your code is not working and can only guess that the likely cause of your problem is in code not shown.
Edit 1:
Just guessing, but you may have a problem of references. I notice that your listener class creates new DisplayForm and Storage objects:
DisplayForm dF = new DisplayForm();
Storage st = new Storage();
There's a good possibility that these objects are not the ones being displayed, especially if you create these objects elsewhere and display them. Again I'm just guessing since I don't see the rest of your code, but perhaps you should to pass references for these objects into the DisplayForm via constructor or setter method parameters.
Edit 2:
e.g.,
public void setDisplayForm(DisplayForm dF) {
this.dF = dF;
}
// same for Storage
And in the main program:
public MainDisplayForm() {
initComponents();
ButtonListener_IncreaseGain btnListenerIncreaseGain = new ButtonListener_IncreaseGain();
btnListenerIncreaseGain.setDisplayForm(....);
btnListenerIncreaseGain.setStorage(....);
Btn_IncreaseGain.addActionListener(btnListenerIncreaseGain);
}
I realise that this is somewhat of an unusual request, since most ViewParts layed out by the workspace and may be in stacks and not have unilateral access to their own size.
However, what i am trying to do is slightly different. I am extending a find-replace bar for eclipse that is reminiscent of the one you see in firefox (and much less obtrusive than the default).
So the desire for this is for it to be a fixed size at the bottom of the editor pane. However, I have not succeeded in setting the size of my view. I have tried
using an ISizeProvider:
public int getSizeFlags(boolean width) {
if (width) {
return SWT.FILL;
}
return SWT.MIN | SWT.MAX;
}
#Override
public int computePreferredSize(boolean width, int availableParallel,
int availablePerpendicular, int preferredResult) {
if (width) {
return preferredResult;
}
return fixedHeight;
}
calling setSize() on my root pane and on its parent pane (NB it is not surprising this doesn't work because the parent's layout manager will likely override it).
Using the internal PartPane class to get the bordering sashes to attempt to move IT programattically. (Don't flame me for doing this, I am just trying to explore the possibilities).
private void updateSize(IWorkbenchPartReference pPartRef) {
// FIXME -- this is all internal stuff. is there a public way to do this?
if (pPartRef instanceof WorkbenchPartReference) {
PartPane lPane = ((WorkbenchPartReference) pPartRef).getPane();
Sashes sashes = new Sashes();
if (lPane.getContainer() != null) {
lPane.getContainer().findSashes(lPane, sashes );
Sash topSash = sashes.top;
if (okToUse(topSash)) {
Rectangle parentBounds = topSash.getParent().getBounds();
int topSashTop = parentBounds.height - fixedHeight - topSash.getSize().y;
sashes.top.setLocation(sashes.top.getLocation().x, topSashTop);
topSash.getParent().layout();
System.out.println("sashtop = " + topSashTop);
}
}
}
}
I've also tried calling PartPane.flushLayout() and PartPane.getContainer.resizeChild() and none of these do anything.
None of this works. Is there a way to achieve what I want?
I am using JTextPane as a table cell renderer to display rich text. When the text is too long to fit inside a cell, it is truncated. I would like to mimic the JLabel behavior, i.e. show ellipsis (...) to alert the user that part of the text is not visible. Has anyone done this before?
Solution I ended up adopting, with help from StanislavL. The algorithm works by chopping off one character at a time off the end of StyledDocument, appending "..." and comparing resulting preferred width to table cell width. This is inefficient, especially in case of very long strings, but not a problem in my case. Can be optimized. The following goes into your renderer's getTableCellRendererComponent
m_dummyTextPane.setDocument(doc);
m_dummyTextPane.setSize(Short.MAX_VALUE, table.getRowHeight());
int width = m_dummyTextPane.getPreferredSize().width;
int start = doc.getLength() - 1;
while(width >= table.getColumnModel().getColumn(col).getWidth() && start>0) {
try {
doc.remove(Math.min(start, doc.getLength()),
doc.getLength() - Math.min(start, doc.getLength()));
doc.insertString(start, "...", null);
} catch (BadLocationException e) {
e.printStackTrace();
break;
}
start--;
width = m_dummyTextPane.getPreferredSize().width;
}
You can use this http://java-sl.com/tip_text_height_measuring.html to measure content for the fixed width. If it requires more space than available just paint something over the JTextPane.
I like the trashgod's idea with scroll too. (+1)
If a scroll bar is an acceptable alternative, but space is at a premium, you may be able to specify a JComponent.sizeVariant, as discussed in Resizing a Component and Using Client Properties.
I did it by just overriding the paint() and getToolTipText() methods, to put it in the tooltip if it's too long:
public void paint(Graphics g)
{
frc=((Graphics2D)g).getFontRenderContext();
super.paint(g);
}
public String getToolTipText(MouseEvent e)
{
String tip=null;
java.awt.Point p=e.getPoint();
int colnum=columnModel.getColumnIndexAtX(p.x);
int rowIndex=rowAtPoint(p);
String field=(String)getModel().getValueAt(rowIndex, colnum);
if (getColumnModel().getColumn(colnum).getWidth()< getFont().getStringBounds(field,frc).getWidth())
{
int i=0;
StringBuffer buf=new StringBuffer("<html>");
while (i<field.length())
{
buf.append(field.substring(i, Math.min(field.length(),i+100)));
buf.append("<br>");
i+=100;
}
tip=buf.toString();
}
return tip;
}