Display text progressively with libgdx - java

I am looking for a way to display text progressively with libgdx, but I can't find a way to do it exactly the way I want. Here is what I did:
I have a text label that is being updated periodically to display a different text. The label is set to setWrap(true); and setAlignment(Align.center);
Every time I change the text of the label I use a custom Action which I built like this
public class DisplayTextAction extends TemporalAction{
private CharSequence completeText;
#Override
protected void update(float percent) {
((Label)actor).setText(
completeText.subSequence(
0,
(int)Math.round(completeText.length()*percent));
}
public void setText(String newText){
completeText = newText;
}
}
Every text update, I call the action from a pool, change the text and add the action to the label.
Here is my problem: This doesn't work the way I want with a centered and wrapped text.
This happens when text isn't centered (dots represent space):
|h........|
|hel......|
|hello....|
(Works as intended)
This is what happens when the text is centered:
|....h....|
|...hel...|
|..hello..|
And this is how I want it to behave:
|..h......|
|..hel....|
|..hello..|
My original idea to fix this was to use 2 sets of strings, one that is the visible text, and one invisible that acts as "padding". I came up with something like this:
CharSequence visibleText = completeText.subSequence(
0,
(int)Math.round(completeText.length()*percent));
CharSequence invisibleText = completeText.subSequence(
(int)Math.round(completeText.length()*percent),
completeText.length());
So I have my two sets of strings, but I can't find a way to display two different fonts (one visible, and another one which is the same but with an alpha of 0) or styles in the same label with Libgdx.
I'm stuck, I don't know if my approach is the right one or if I should look into something completely different, and if my approach is correct, I don't know how to follow it up using libgdx tools.
EDIT:
I followed Jyro117's instructions and I could make great progress, but I couldn't make it work with centred text on multiple lines.
imagine this text:
|all those lines are|
|..for a very long..|
|........text.......|
And it has to be displayed like this
|all th.............|
|...................|
|...................|
|all those line.....|
|...................|
|...................|
|all those lines are|
|..for a ve.........|
|...................|
|all those lines are|
|..for a very long..|
|........text.......|
Jyro117's solution give either
|all those lines are|
|for a very long....|
|text...............|
displayed correctly.
or
|...................|
|......all tho......|
|...................|
|...................|
|...all those lin...|
|...................|
|all those lines are|
|......for a v......|
|...................|

You are over-complicating the solution. All you really need is to determine the size of the label when all the text is added. Once you have determined that, lock the label size to those dimensions, put it inside of a table that expands to fill up the area around it, and then update your label with the action. (You can use a pool and such as needed, but for simplicity I left that out of the code below).
You will have to obviously adapt the code to yours, but this gives you a code reference to what I mean.
Here is a code snippet on one way to do it:
stage = new Stage(Gdx.graphics.getWidth(), Gdx.graphics.getHeight(), false);
Gdx.input.setInputProcessor(stage);
uiSkin = new Skin(Gdx.files.internal("skin/uiskin.json"));
Table fullScreenTable = new Table();
fullScreenTable.setFillParent(true);
final String message = "hello";
final Label progressLabel = new Label(message, this.uiSkin);
final TextBounds bounds = progressLabel.getTextBounds(); // Get libgdx to calc the bounds
final float width = bounds.width;
final float height = bounds.height;
progressLabel.setText(""); // clear the text since we want to fill it later
progressLabel.setAlignment(Align.CENTER | Align.TOP); // Center the text
Table progressTable = new Table();
progressTable.add(progressLabel).expand().size(width, height).pad(10);
final float duration = 3.0f;
final TextButton button = new TextButton("Go!", this.uiSkin);
button.addListener(new ClickListener() {
#Override public void clicked(InputEvent event, float x, float y) {
progressLabel.addAction(new TemporalAction(duration){
LabelFormatter formatter = new LabelFormatter(message);
#Override protected void update(float percent) {
progressLabel.setText(formatter.getText(percent));
}
});
}
});
stage.addActor(button);
fullScreenTable.add(progressTable);
fullScreenTable.row();
fullScreenTable.add(button);
stage.addActor(fullScreenTable);
Edit:
Added code to center and top align text in label. Also added code to fill spaces on the end to allow for proper alignment. Note: Only useful for mono-spaced fonts.
class LabelFormatter {
private final int textLength;
private final String[] data;
private final StringBuilder textBuilder;
LabelFormatter(String text) {
this.textBuilder = new StringBuilder();
this.data = text.split("\n");
int temp = 0;
for (int i = 0 ; i < data.length; i++) {
temp += data[i].length();
}
textLength = temp;
}
String getText(float percent) {
textBuilder.delete(0, textBuilder.length());
int current = Math.round(percent * textLength);
for (final String row : data) {
current -= row.length();
if (current >= 0) {
textBuilder.append(row);
if (current != 0) {
textBuilder.append('\n');
}
} else {
textBuilder.append(row.substring(0, row.length() + current));
// Back fill spaces for partial line
for (int i = 0; i < -current; i++) {
textBuilder.append(' ');
}
}
if (current <= 0) {
break;
}
}
return textBuilder.toString();
}
}

Related

Java Swing Double-click + drag to select whole words

In most text editors and platforms there are two ways of selecting text using the mouse:
The regular, Click+Drag, moves the end of the selection along with the mouse cursor
Double-click+Drag, same as #1 but it starts by selecting one whole word, and then snaps the end of the selection to whole words
In Swing GUI however, #2 does not work as above. It starts correctly by selecting the whole word where the double-click was, but then it does not snap to whole words during selection.
Is there any way to get Swing text fields to behave as 2, with the selection snapping to whole words?
You can create a method to calculate the index of where word your selection ends and starts. See below:
int getWordEndPos(String text, int initPos) {
int i = initPos;
while(Character.isAlphabetic(text.charAt(i))) {
i++;
}
return i;
}
int getWordStartPos(String text, int initPos) {
int i = initPos;
while(Character.isAlphabetic(text.charAt(i))) {
i--;
}
return i+1;
}
Then in your UI (not sure exactly how JTextArea works) you could get the start and end position of your selection, and actually selects the start and end position of their words:
void updateSelection(JTextArea ta) {
String text = ta.getText();
int start = ta.getSelectionStart();
int end = ta.getSelectionEnd();
start = getWordStartPos(text, start);
end = getWordEndPos(text, end);
ta.select(start, end);
}
But where to call the snippet above? You could listen to CarretEvent instead of MouseEvent (see Which event a selection of text trigger in Java JTextArea?):
textArea.addCarretListener((evt) -> updateSelection(textArea));
But another problem arrises: how to know the click count of MouseEvent. You could make an attribute to store it, and then into the mouse event listener, it can be set. The code below tries to put everything toghether:
class UI implements MouseListener, CarretListener {
JTextArea textArea;
int clickCount = 0;
UI() {
textArea.addCarretListener(this);
textArea.addMouseListener(this);
// ...
}
#Override
void mouseClicked(MouseEvent evt) {
this.clickCount = evt.getClickCount();
// other stuff
}
// other MouseListener methods
#Override
void caretUpdate(CaretEvent evt) {
if (clickCount == 1) updateSelection(textArea);
// other caret listener stuff
}
void updateSelection(JTextArea ta) {
String text = ta.getText();
int start = ta.getSelectionStart();
int end = ta.getSelectionEnd();
start = getWordStartPos(text, start);
end = getWordEndPos(text, end);
ta.select(start, end);
}
}

JavaFX TableView with two fixed-columns and last one taking available space

I'm trying to make a simple 3-column TableView:
One icon column containing a fixed size icon. This column must not be resizable, and must have a fixed size.
One text column with a predefined prefered size, which can be resized if needed.
One last column taking all available space.
Unfortunatly, this simple use case seems to be really complicated with Java FX 8. I tried the following, which should work according to my understanding of the documentation:
TableColumn<DebuggerItem, ImageView> iconColumn = new TableColumn<>("ICON");
TableColumn<DebuggerItem, String> typeColumn = new TableColumn<>("TEXT");
TableColumn<DebuggerItem, String> textColumn = new TableColumn<>("DATA");
setColumnResizePolicy(CONSTRAINED_RESIZE_POLICY);
// Fixed size column
iconColumn.setPrefWidth(40);
iconColumn.setMinWidth(40);
iconColumn.setMaxWidth(40);
iconColumn.setResizable(false);
// Predefined preferred size of 100px
typeColumn.setPrefWidth(100);
getColumns().addAll(iconColumn, typeColumn, textColumn);
This results in the following TableView:
We can see that if the first column has a correct size, the second and the hird have the same size, which is not what I expected. The second column should be 100px wide, and the last one take the rest of the space.
What did I miss ?
According to #kleopatra link, the solution is to use properties to compute last column width, and NOT use CONSTRAINED_RESIZE_POLICY :
LastColumnWidth = TableViewWidth - SUM(Other Columns Widths)
Which, according to my example give the following Java code:
TableColumn<DebuggerItem, ImageView> iconColumn = new TableColumn<>("ICON");
TableColumn<DebuggerItem, String> typeColumn = new TableColumn<>("TEXT");
TableColumn<DebuggerItem, String> textColumn = new TableColumn<>("DATA");
// Fixed size column
iconColumn.setPrefWidth(40);
iconColumn.setMinWidth(40);
iconColumn.setMaxWidth(40);
iconColumn.setResizable(false);
// Predefined preferred size of 100px
typeColumn.setPrefWidth(100);
// Automatic width for last column
textColumn.prefWidthProperty().bind(
widthProperty().subtract(
iconColumn.widthProperty()).subtract(
typeColumn.widthProperty()).subtract(2)
);
getColumns().addAll(iconColumn, typeColumn, textColumn);
Please note that we need to substract 2 pixels to get the exact width, it's not clear why.
I created a more general solution, that pixel-perfectly calculates width of last column for TableViews that:
have any number of columns
possibly hide or show columns at runtime
possibly have custom insets
possibly have scrollbar, possibly showing and hiding at runtime.
Usage:
bindLastColumnWidth(tableView);
Source:
public static <T> void bindLastColumnWidth (TableView<T> tableView) {
List<TableColumn<T,?>> columns = tableView.getColumns();
List<TableColumn<T,?>> columnsWithoutLast = columns.subList(0, columns.size() - 1);
TableColumn lastColumn = columns.get(columns.size() - 1);
NumberExpression expression = tableView.widthProperty();
Insets insets = tableView.getInsets();
expression = expression.subtract(insets.getLeft() + insets.getRight());
for (TableColumn column : columnsWithoutLast) {
NumberExpression columnWidth = Bindings.when(column.visibleProperty())
.then(column.widthProperty())
.otherwise(0);
expression = expression.subtract(columnWidth);
}
ScrollBar verticalScrollBar = getScrollBar(tableView, Orientation.VERTICAL);
if (verticalScrollBar != null) {
NumberExpression scrollBarWidth = Bindings.when(verticalScrollBar.visibleProperty())
.then(verticalScrollBar.widthProperty())
.otherwise(0);
expression = expression.subtract(scrollBarWidth);
}
expression = Bindings.max(lastColumn.getPrefWidth(), expression);
lastColumn.prefWidthProperty().bind(expression);
}
private static ScrollBar getScrollBar (Node control, Orientation orientation) {
for (Node node : control.lookupAll(".scroll-bar")) {
if (node instanceof ScrollBar) {
ScrollBar scrollBar = (ScrollBar)node;
if (scrollBar.getOrientation().equals(orientation)) {
return scrollBar;
}
}
}
return null;
}
You can call this below code after you add all columns to table.
This is nice when the code that resizes does not have a explicit list of columns.
public static void makeLastColumnGrow(TableView<?> items) {
var last = items.getColumns().get(items.getColumns().size() - 1);
var aBinding = Bindings.createDoubleBinding(() ->{
double width = items.getWidth();
for (int i = 0; i < items.getColumns().size() - 1 ; i++) {
width = width - items.getColumns().get(i).getWidth();
}
return width - 2; // minus -2 to account for border i think
}, items.widthProperty());
last.prefWidthProperty().bind(aBinding);
}

paintitem and indexoutofbounds error

I have create a table with bars which shows frequency of the words in a text.I show the number of special word which user click on them or frequency of whole words in the text. I fetch my list of list and send it to the fill table function. All thing is OK but when I select a special word and then click to show whole words I get indexoutofbounds exception. I guess it is because I change my datasource. It is really strange but simple. However, I could not solve it.
public void fill_count_table(List<RootWordSet> source){
final List<RootWordSet> mysource=source;
if(source!=null){
for(int i=0;i<source.size();i++){
TableItem ti=new TableItem(count_table, SWT.NONE);
ti.setText(source.get(i).getRoot());
}
count_table.addListener(SWT.PaintItem, new Listener() {
public void handleEvent(Event event) {
if (event.index == 1) {
try{
GC gc = event.gc;
TableItem item = (TableItem)event.item;
int index = count_table.indexOf(item);
System.out.println(mysource.size());
int percent = mysource.get(index).getWordNumber();
org.eclipse.swt.graphics.Color foreground = gc.getForeground();
org.eclipse.swt.graphics.Color background = gc.getBackground();
gc.setForeground(Display_1.getSystemColor(SWT.COLOR_BLUE));
gc.setBackground(Display_1.getSystemColor(SWT.COLOR_DARK_BLUE));
int width = (tc2.getWidth() - 1) * percent / 100;
gc.fillGradientRectangle(event.x, event.y, width, event.height, true);
Rectangle rect2 = new Rectangle(event.x, event.y, width-1, event.height-1);
gc.drawRectangle(rect2);
gc.setForeground(Display_1.getSystemColor(SWT.COLOR_RED));
String text = Integer.toString(percent) ;
Point size = event.gc.textExtent(text);
int offset = Math.max(0, (event.height - size.y) / 2);
gc.drawText(text, event.x+2, event.y+offset, true);
gc.setForeground(background);
gc.setBackground(foreground);
}
catch(Exception e){
System.out.println(e.getMessage());
e.printStackTrace();
}
}
}
});
}
else{
count_table.removeAll();
count_table.redraw();
}
}
this is the line that make error: int percent = mysource.get(index).getWordNumber();
I really do not know what happens when I change datasources. when I shift to each other it stuck. Even I put a println to check the size of datasource but it was quite strange it had two size. One belong to former datasource and one belong to newwr. Anyway If I remove this graphic part table fill correctly. What do you think?
change this line:
int percent = mysource.get(index).getWordNumber();
to
int percent = mysource.get(index-1).getWordNumber();

Which text margin does SWT Table use when drawing text?

I got a relatively easy question - but I cannot find anything anywhere to answer it.
I use a simple SWT table widget in my application that displays only text in the cells. I got an incremental search feature and want to highlight text snippets in all cells if they match.
So when typing "a", all "a"s should be highlighted.
To get this, I add an SWT.EraseItem listener to interfere with the background drawing. If the current cell's text contains the search string, I find the positions and calculate relative x-coordinates within the text using event.gc.stringExtent - easy.
With that I just draw rectangles "behind" the occurrences.
Now, there's a flaw in this. The table does not draw the text without a margin, so my x coordinate does not really match - it is slightly off by a few pixels! But how many?? Where do I retrieve the cell's text margins that table's own drawing will use? No clue. Cannot find anything.
Bonus question: the table's draw method also shortens text and adds "..." if it does not fit into the cell. Hmm. My occurrence finder takes the TableItem's text and thus also tries to mark occurrences that are actually not visible because they are consumed by the "...".
How do I get the shortened text and not the "real" text within the EraseItem draw handler?
#Override
public void handleEvent( final Event event ) {
final TableItem ti = (TableItem) event.item;
final int index = event.index;
final GC gc = event.gc;
if( ti == null || currentSwyt.isEmpty() ) {
return;
}
final String text = ti.getText( index );
if( !text.contains( currentSwyt ) ) {
return;
}
// search text is contained
final String[] parts = text.split( currentSwyt );
final int swytWidth = gc.stringExtent( currentSwyt ).x;
// calculate positions, must be relative to the text's start
int x = event.x; // THIS IS THE PROBLEM: event.x is not enough!
final int[] pos = new int[parts.length - 1];
for( int i = 0; i < parts.length - 1; i++ ) {
x += gc.stringExtent( parts[i] ).x;
pos[i] = x;
}
final Color red = event.display.getSystemColor( SWT.COLOR_RED );
final Color oldBackground = gc.getBackground();
gc.setBackground( red );
for( int j = 0; j < pos.length; j++ ) {
gc.fillRectangle( pos[j], event.y, swytWidth, event.height );
}
gc.setBackground( oldBackground );
event.detail &= ~SWT.BACKGROUND;
}
I think it would be quite useful for you to have a look at TableViewer and StyledCellLabelProvider. That will make your task a lot easier I think considering the kind of text formatting you require. Since the drawing is than completely handled by the label provider, you can avoid these pesky margin issues.
As for almost all SWT Widgets, this might be OS dependent. The actual "drawing" of the table is done using OS resources.
However, it might be worth having a look at TableItem#getTextBounds(int).
It returns a Rectangle that should reflect the margins.
For your bonus question: I have never seen the text being shortened automatically in my applications. In fact I had a hard time doing this myself. But that might as well be OS dependent, since I use Linux.

Creating custom swing component out of existing

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;
}
}
}
}

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