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| Re: TreeViewer, how to jump say what element to show on top? [message #1123213 is a reply to message #1123124] |
Wed, 02 October 2013 06:15   |
Eclipse User |
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Hi,
probably it is to easy to be the proper solution but try this:
treeViewer.getTree().setTopItem(toBeToRevealed);
Here is the modified Snippet002TreeViewer showing the functionality:
import java.util.ArrayList;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.TreeItem;
/**
* A simple TreeViewer to demonstrate usage
*
* @author Tom Schindl <tom.schindl@bestsolution.at>
*
*/
public class Snippet002TreeViewer {
private class MyContentProvider implements ITreeContentProvider {
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.IStructuredContentProvider#getElements(java.lang.Object)
*/
public Object[] getElements(Object inputElement) {
return ((MyModel)inputElement).child.toArray();
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.IContentProvider#dispose()
*/
public void dispose() {
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.IContentProvider#inputChanged(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
*/
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITreeContentProvider#getChildren(java.lang.Object)
*/
public Object[] getChildren(Object parentElement) {
return getElements(parentElement);
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITreeContentProvider#getParent(java.lang.Object)
*/
public Object getParent(Object element) {
if( element == null) {
return null;
}
return ((MyModel)element).parent;
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITreeContentProvider#hasChildren(java.lang.Object)
*/
public boolean hasChildren(Object element) {
return ((MyModel)element).child.size() > 0;
}
}
public class MyModel {
public MyModel parent;
public ArrayList child = new ArrayList();
public int counter;
public MyModel(int counter, MyModel parent) {
this.parent = parent;
this.counter = counter;
}
public String toString() {
String rv = "Item ";
if( parent != null ) {
rv = parent.toString() + ".";
}
rv += counter;
return rv;
}
}
public Snippet002TreeViewer(Shell shell) {
shell.setLayout(new GridLayout());
final TreeViewer v = new TreeViewer(shell);
v.setLabelProvider(new LabelProvider());
v.setContentProvider(new MyContentProvider());
v.setInput(createModel());
v.getTree().setLayoutData(new GridData(GridData.FILL_BOTH));
Button button = new Button(shell, SWT.NONE);
button.setText("Scroll");
button.addSelectionListener(new SelectionListener() {
@Override
public void widgetSelected(SelectionEvent e) {
TreeItem[] items = v.getTree().getItems();
TreeItem toBeToRevealed = null;
for (TreeItem item: items)
{
MyModel modelData = (MyModel) item.getData();
if (modelData.counter == 50)
{
toBeToRevealed = item;
}
}
v.getTree().setTopItem(toBeToRevealed);
}
@Override
public void widgetDefaultSelected(SelectionEvent e) {
}
});
}
private MyModel createModel() {
MyModel root = new MyModel(0,null);
root.counter = 0;
MyModel tmp;
for( int i = 1; i < 100; i++ ) {
tmp = new MyModel(i, root);
root.child.add(tmp);
for( int j = 1; j < i; j++ ) {
tmp.child.add(new MyModel(j,tmp));
}
}
return root;
}
public static void main(String[] args) {
Display display = new Display ();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
new Snippet002TreeViewer(shell);
shell.open ();
while (!shell.isDisposed ()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}
}
HTH
Thorsten
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| Re: TreeViewer, how to jump say what element to show on top? [message #1123278 is a reply to message #1123241] |
Wed, 02 October 2013 07:50 |
| Eclipse User |
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Here you go now. It's basically the same as above.
Use:
and
treeViewer.getTree().setTopItem()
Hope this time it helps.
Thorsten
Working example:
import java.util.ArrayList;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.TreeItem;
/**
* A simple TreeViewer to demonstrate usage
*
* @author Tom Schindl <tom.schindl@bestsolution.at>
*
*/
public class Snippet002TreeViewer {
private static int sequence = 0;
private class MyContentProvider implements ITreeContentProvider {
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.IStructuredContentProvider#getElements(java.lang.Object)
*/
public Object[] getElements(Object inputElement) {
return ((MyModel)inputElement).child.toArray();
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.IContentProvider#dispose()
*/
public void dispose() {
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.IContentProvider#inputChanged(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
*/
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITreeContentProvider#getChildren(java.lang.Object)
*/
public Object[] getChildren(Object parentElement) {
return getElements(parentElement);
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITreeContentProvider#getParent(java.lang.Object)
*/
public Object getParent(Object element) {
if( element == null) {
return null;
}
return ((MyModel)element).parent;
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITreeContentProvider#hasChildren(java.lang.Object)
*/
public boolean hasChildren(Object element) {
return ((MyModel)element).child.size() > 0;
}
}
public class MyModel {
public MyModel parent;
public ArrayList child = new ArrayList();
public int counter;
public int id;
public MyModel(int id) {
this.id = id;
}
public MyModel(int counter, MyModel parent) {
this.parent = parent;
this.counter = counter;
this.id = sequence++;
}
public String toString() {
String rv = "Item ";
if( parent != null ) {
rv = parent.toString() + ".";
}
rv += counter;
rv += "("+id+")";
return rv;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + getOuterType().hashCode();
result = prime * result + id;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
MyModel other = (MyModel) obj;
if (!getOuterType().equals(other.getOuterType()))
return false;
if (id != other.id)
return false;
return true;
}
private Snippet002TreeViewer getOuterType() {
return Snippet002TreeViewer.this;
}
}
public Snippet002TreeViewer(Shell shell) {
shell.setLayout(new GridLayout());
final TreeViewer v = new TreeViewer(shell);
v.setLabelProvider(new LabelProvider());
v.setContentProvider(new MyContentProvider());
v.setInput(createModel());
v.getTree().setLayoutData(new GridData(GridData.FILL_BOTH));
Button button = new Button(shell, SWT.NONE);
button.setText("Scroll");
button.addSelectionListener(new SelectionListener() {
@Override
public void widgetSelected(SelectionEvent e) {
// I don't know how you want to define the Item to top. I assume you go via a TreePath.
// Path to the element to set to top
final TreePath path = new TreePath(new MyModel[]{new MyModel(1036), new MyModel(1059)});
// First make sure the item to be set to top is visible
v.reveal(path);
// Find the item to top
TreeItem toBeToRevealed = getItemToTop(path);
if (toBeToRevealed!=null)
{
v.getTree().setTopItem(toBeToRevealed);
TreeItem topItem = v.getTree().getTopItem();
if (topItem!=toBeToRevealed)
{
System.err.println("failed to reveal element at top!");
}
}
}
@Override
public void widgetDefaultSelected(SelectionEvent e) {
}
private TreeItem getItemToTop(TreePath path) {
// You might subclass TreeViewer to be able to access findItem(path).
// Here: use recursive approach via TreeItems.
TreeItem[] items = v.getTree().getItems();
return findItem(path, items, 0);
}
private TreeItem findItem(TreePath path, TreeItem[] items, int lvl) {
if (items==null)
{
return null;
}
Object segment = path.getSegment(lvl);
for (TreeItem item: items)
{
MyModel itemData = (MyModel) item.getData();
if (itemData!=null && itemData.equals(segment))
{
if (lvl==path.getSegmentCount()-1)
{
return item;
}
else
{
TreeItem toBeRevealed = findItem(path, item.getItems(), ++lvl);
return toBeRevealed;
}
}
}
return null;
}
}
);
}
private MyModel createModel() {
MyModel root = new MyModel(0,null);
root.counter = 0;
MyModel tmp;
for( int i = 1; i < 100; i++ ) {
tmp = new MyModel(i, root);
root.child.add(tmp);
for( int j = 1; j < i; j++ ) {
tmp.child.add(new MyModel(j,tmp));
}
}
return root;
}
public static void main(String[] args) {
Display display = new Display ();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
new Snippet002TreeViewer(shell);
shell.open ();
while (!shell.isDisposed ()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}
}
[Updated on: Wed, 02 October 2013 07:51] by Moderator |
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| Re: TreeViewer, how to jump say what element to show on top? [message #1123473 is a reply to message #1123278] |
Wed, 02 October 2013 11:51 |
| Eclipse User |
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Thanks, but setInput, doesn't change the root? What I want is not to set the root to B, which result in the example would be:
__________
B
____
(B on the top-left and its children hanging -in this example none-).
But to show the B element on top (not top-left), so the equivalent to scrolling it up or down until the element is in the first visible row. In other words, I don't want to change the model, I want to apply the view to show other part of the model.
_________
B
C
_________
Thanks again,
Luis
[Updated on: Wed, 02 October 2013 11:52] by Moderator |
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| Re: TreeViewer, how to jump say what element to show on top? [message #1863543 is a reply to message #1129309] |
Thu, 08 February 2024 04:41 |
| Eclipse User |
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Hi
I want to ask that when we use eclipse modelling framework to generate code.
And at the runtime, we can see the tree like structure. If i am not at the top left node and i want to go upside towards the top left node can i do that. If yes, how?
A little bit more explain.. about question:
A
...B
...C
.......D
if i am at D i know i can move downwards by using it's object and properties but can i move towards the topleft like First C then B then A.
Thanks in advance
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. In any case I appreciate that you also suggested me to extend that, because although I was doing it, I was a little bit scared. TreeViewer documentation states that "TreeViewer is not intended to be subclassed" but I have no idea why. It made a lot of sense for me (and I tend to encapsulate things a lot and inheritance is many times a great approach), and it does work.