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| [Databinding] bind modify of text to boolean [message #335952] |
Mon, 11 May 2009 14:02  |
 rollo
Messages: 117
Registered: July 2009 |
Senior Member |
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Hi,
I'm quite new to eclipse databinding.
I have a Text which is bind to model.
public static void bindTextToValue( Text text, Object object, String
propertyName, IValidator validator ) {
ISWTObservableValue textValue = SWTObservables.observeText( text,
SWT.Modify );
IObservableValue objectValue = BeansObservables.observeValue(
getRealm(), object, propertyName );
UpdateValueStrategy strategy = new UpdateValueStrategy();
strategy.setAfterGetValidator( validator );
getContext().bindValue( textValue, objectValue, strategy, strategy );
}
This works.
But now I want to bind the text also to a boolean value, to notify if
the text has changed.
I did it like that:
ISWTObservableValue targetObservableValue = SWTObservables.observeText(
text, SWT.Modify );
IObservableValue modelObservableValue = BeansObservables.observeValue(
this, "changed" );
getContext().bindValue( targetObservableValue, modelObservableValue );
I want that the boolean "changed" is set to "true" if the user modify
the text.
Is it possible to bind selveral things to one text?
Roland
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| Re: [Databinding] bind modify of text to boolean [message #335975 is a reply to message #335959] |
Tue, 12 May 2009 11:55  |
rollo
Messages: 117
Registered: July 2009 |
Senior Member |
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This is a multi-part message in MIME format.
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Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 7bit
Hi Matthew,
Thank you very much. Your explanation really helped.
Now I have only one problem.
When I select the "saveButton", which was enabled when the "changed" was
set to "true", "changed" should set back to "false".
But I can't get it working.
I attached a little snippet.
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Content-Type: text/plain;
name="TestSnippet.java"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="TestSnippet.java"
package org.eclipse.jface.examples.databinding.snippets;
import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.UpdateValueStrategy;
import org.eclipse.core.databinding.beans.PojoObservables;
import org.eclipse.core.databinding.conversion.IConverter;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.value.ComputedValue;
import org.eclipse.core.databinding.observable.value.IObservableVal ue;
import org.eclipse.jface.databinding.swt.ISWTObservableValue;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class TestSnippet {
static Person person = new Person("John", "Smith");
public static void main(String[] args) {
Display display = new Display();
Realm.runWithDefault(SWTObservables.getRealm(display), new Runnable() {
public void run() {
Display display = Display.getCurrent();
Shell shell = new Shell(display);
shell.setLayout(new RowLayout(SWT.VERTICAL));
Text first = new Text(shell, SWT.BORDER);
Text last = new Text(shell, SWT.BORDER);
Button button = new Button(shell, SWT.NONE);
button.setText("Save");
button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
// save...
}
});
// here comes the binding
DataBindingContext context = new DataBindingContext();
// bind first to Person#firstName
ISWTObservableValue firstValue = SWTObservables.observeText(
first, SWT.Modify);
IObservableValue firstModelValue = PojoObservables
.observeValue(person, "firstName");
context.bindValue(firstValue, firstModelValue,
new UpdateValueStrategy(), new UpdateValueStrategy());
// bind last to Person#lastName
ISWTObservableValue lastValue = SWTObservables.observeText(
last, SWT.Modify);
IObservableValue lastModelValue = PojoObservables.observeValue(
person, "lastName");
context.bindValue(lastValue, lastModelValue,
new UpdateValueStrategy(), new UpdateValueStrategy());
// bind modify of first/last to dirty
IObservableValue needSavingValue = PojoObservables
.observeValue(person, "needSaving");
UpdateValueStrategy t2m = new UpdateValueStrategy();
t2m.setConverter(new IConverter() {
public Object convert(Object fromObject) {
return Boolean.TRUE;
}
public Object getFromType() {
return String.class;
}
public Object getToType() {
return Boolean.class;
}
});
context.bindValue(firstValue, needSavingValue, t2m,
new UpdateValueStrategy(
UpdateValueStrategy.POLICY_NEVER));
context.bindValue(lastValue, needSavingValue, t2m,
new UpdateValueStrategy(
UpdateValueStrategy.POLICY_NEVER));
// bind the button to dirty - enable when dirty
ISWTObservableValue enableValue = SWTObservables
.observeEnabled(button);
context.bindValue(enableValue, needSavingValue,
new UpdateValueStrategy(), new UpdateValueStrategy());
// TODO bind the selection of button to dirty
final ISWTObservableValue buttonselectValue = SWTObservables
.observeSelection(button);
ComputedValue value = new ComputedValue(Boolean.TYPE) {
protected Object calculate() {
return new Boolean(!((Boolean) buttonselectValue
.getValue()).booleanValue());
}
};
context.bindValue(value, needSavingValue,
new UpdateValueStrategy(), new UpdateValueStrategy(
UpdateValueStrategy.POLICY_NEVER));
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
});
}
static class Person {
private String firstName;
private String lastName;
boolean needSaving;
public Person(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public void setFirstName(String firstName) {
System.err.println("firstName changed from '" + this.firstName
+ "' to '" + firstName + "'.");
this.firstName = firstName;
}
public String getFirstName() {
return firstName;
}
public void setLastName(String lastName) {
System.err.println("lastName changed from '" + this.lastName
+ "' to '" + lastName + "'.");
this.lastName = lastName;
}
public String getLastName() {
return lastName;
}
public void setNeedSaving(boolean needSaving) {
System.err.println("needSaving changed from '" + this.needSaving
+ "' to '" + needSaving + "'.");
this.needSaving = needSaving;
}
public boolean isNeedSaving() {
return needSaving;
}
}
}
--------------030703080209030208070609--
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| Re: [Databinding] bind modify of text to boolean [message #335983 is a reply to message #335975] |
Tue, 12 May 2009 18:17 |
Eclipse User |
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Originally posted by: eclipse-news.rizzoweb.com
Roland wrote:
> Hi Matthew,
>
> Thank you very much. Your explanation really helped.
>
> Now I have only one problem.
> When I select the "saveButton", which was enabled when the "changed" was
> set to "true", "changed" should set back to "false".
In the event handler of the Save button, it will need to set the model
value back to false [call setNeedSaving(false)]. As long as you've set
up the binding correctly (bi-directional), that should automatically
make the button disabled again.
Hope this helps,
Eric
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