Attachment 111773 Details for Bug 235583 – Enhanced snippet to illustrate selection problem with table more clearly

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Enhanced snippet to illustrate selection problem with table more clearly

clipboard.txt (text/plain), 8.12 KB, created by Stefan Röck

on 2008-09-05 03:05:58 EDT

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Creator: Stefan Röck

Created: 2008-09-05 03:05:58 EDT

Size: 8.12 KB

patch

obsolete

>public class VirtualTableTest{
>    
>    private static final int DB_FETCH_DELAY = 200;
>	private static final int ADD_ENTRIES = 100;
>    private static final int PREFETCH_TRESHOLD = 50;
>    private static final int MAX_ENTRIES= 208;
>    
>    private int rowcounter = 0;
>    
>    private List<String> model = new ArrayList<String>();
>    
>    private void createContent(Composite parent) {
>        initModel();
>        
>        Composite container = new Composite(parent, SWT.NONE);
>        container.setLayout(new GridLayout(1, false));
>
>        final TableViewer tableViewer = new TableViewer(container, SWT.VIRTUAL | SWT.BORDER | SWT.MULTI);
>        tableViewer.setContentProvider(new ILazyContentProvider(){
>
>            public void updateElement(int index){
>                if (index >= 0 && index <tableViewer.getTable().getItemCount()) {
>                	if (index > getModel().size() - PREFETCH_TRESHOLD && (getModel().size() < MAX_ENTRIES)) {
>                		// simulate loading the next page of data from db
>                		int approxRecordCount = addElementsToModel();
>                		
>                		System.out.println("approx. record count: " + approxRecordCount);
>                		tableViewer.setItemCount(approxRecordCount);
>                		updateRowCountStatus(tableViewer);
>                	}
>                	if (index < getModel().size()) {
>                		tableViewer.replace(getModel().get(index), index);
>                	} else {
>                    	System.out.println("invalid index " + index + " model count " + getModel().size());
>                	}
>                } else {
>                	System.out.println("invalid index " + index + " tableItemCount " + tableViewer.getTable().getItemCount());
>                }
>            }
>
>            public void dispose(){
>            }
>
>            public void inputChanged(Viewer arg0, Object arg1, Object arg2){
>            }
>        });
>        String[] columnProperties = new String[] { "Spalte 1", "Virtual Tables rock" };
>        tableViewer.setColumnProperties(columnProperties);
>
>        final Table table = tableViewer.getTable();
>        
>        TableColumn col = new TableColumn(table, SWT.NONE);
>        col.setText(columnProperties[0]);
>        col.setWidth(200);
>        
>        col = new TableColumn(table, SWT.NONE);
>        col.setText(columnProperties[1]);
>        col.setWidth(400);
>        
>        table.setHeaderVisible(true);
>        table.setLinesVisible(true);
>
>        GridDataFactory.fillDefaults().grab(true, true).applyTo(tableViewer.getTable());
>        tableViewer.setItemCount(getModel().size());
>        tableViewer.setInput(getModel());
>
>        table.setSelection(0);
>        
>        updateRowCountStatus(tableViewer);
>        
>        Button btn;
>        
>        btn = new Button(container, SWT.PUSH);
>        btn.setText("Clear table");
>        btn.addSelectionListener(new SelectionAdapter(){
>
>            @Override
>            public void widgetSelected(SelectionEvent e){
>                tableViewer.setItemCount(0);
>                updateRowCountStatus(tableViewer);
>            }
>
>        });
>        
>        btn = new Button(container, SWT.PUSH);
>        btn.setText("Delete selected rows");
>        btn.addSelectionListener(new SelectionAdapter(){
>
>            @Override
>            public void widgetSelected(SelectionEvent e){
>                ISelection sel = tableViewer.getSelection();
>                if (sel instanceof IStructuredSelection) {
>                    IStructuredSelection structSel = (IStructuredSelection) sel;
>                    Iterator iterator = structSel.iterator();
>                    
>                    // remove selected elements from model
>                    while (iterator.hasNext()) {
>                        Object element = iterator.next();
>                        getModel().remove(element);
>                    }
>                    
>                    // refresh TableViewer
>                    try {
>                        tableViewer.setItemCount(getModel().size());
>                        tableViewer.refresh();
>                        tableViewer.setSelection(null);
>                        tableViewer.getTable().setTopIndex(0);
>                        
>                        tableViewer.getTable().setSelection(0);
>                        
>                        updateRowCountStatus(tableViewer);
>                        
>                    } catch (Exception exc) {
>                        System.out.println("ERROR on table refresh");
>                        exc.printStackTrace();
>                    }
>                }
>            }
>
>        });
>
>        btn = new Button(container, SWT.PUSH);
>        btn.setText("Load new list");
>        btn.addSelectionListener(new SelectionAdapter(){
>
>            @Override
>            public void widgetSelected(SelectionEvent e){
>                initModel();
>                tableViewer.setSelection(null);
>                tableViewer.getTable().setTopIndex(0);
>                tableViewer.setItemCount(getModel().size());
>                tableViewer.refresh();
>                
>                tableViewer.getTable().setSelection(0);
>                
>                updateRowCountStatus(tableViewer);
>            }
>            
>        });
>        
>        table.addSelectionListener(new SelectionAdapter() {
>        	@Override
>        	public void widgetSelected(SelectionEvent e) {
>        		updateRowCountStatus(tableViewer);
>        	}
>        	
>        });
>    }
>    
>    
>    // Methods returns an approximate record count which is always
>    // one page size larger than the actually fetched records, until
>    // all records have been fetched and the end of list has been reached.
>    protected int addElementsToModel(){
>        int approxRecordCount = 0;
>    	int itemsToAdd;
>    	
>        if (getModel().size() + ADD_ENTRIES < MAX_ENTRIES) {
>    		itemsToAdd = ADD_ENTRIES;
>        } else {
>        	itemsToAdd = MAX_ENTRIES - getModel().size();
>        }
>    	
>    	for (int i = 0; i < itemsToAdd; i++) {
>			getModel().add("Item " + this.rowcounter++);
>		}
>    	
>    	if (getModel().size() == MAX_ENTRIES) {
>    		approxRecordCount = MAX_ENTRIES;
>    	} else {
>    		approxRecordCount = getModel().size() + ADD_ENTRIES;
>    	}
>    	
>    	simulateSlowDBQuery();
>    	return approxRecordCount;
>    }
>    
>
>    // simulated time which is needed to perform a db query
>    private void simulateSlowDBQuery() {
>    	try {
>			Thread.sleep(DB_FETCH_DELAY);
>		} catch (InterruptedException e) {
>			e.printStackTrace();
>		}
>	}    
>
>	private void initModel(){
>        this.rowcounter = 0;
>        getModel().clear();
>        addElementsToModel(); 
>    }
>
>    private List<String> getModel(){
>        return this.model;
>    }
>
>    public int runTableTest(Display display){
>        final Shell mainShell = new Shell(display, SWT.DIALOG_TRIM | SWT.RESIZE | SWT.MAX);
>        mainShell.setLayout(new FillLayout());
>        mainShell.setMaximized(true);
>        
>        
>        createContent(mainShell);
>        
>        mainShell.addShellListener(new ShellAdapter() {
>
>
>            @Override
>            public void shellClosed(ShellEvent e){
>                mainShell.dispose();
>            }
>        });
>        
>        mainShell.open();
>        while( !mainShell.isDisposed() ) {
>          if( !display.readAndDispatch() ) {
>            display.sleep();
>          }
>        }
>        
>        return 0;
>    }
>
>    private void updateRowCountStatus(final TableViewer tableViewer){
>        final Table table = tableViewer.getTable();
>		String shellCaption = getModel().size() + " rows";
>		
>        if (table.getSelectionCount() > 0) {
>			String selectionIdx = null;
>        	for (int idx: table.getSelectionIndices()) {
>				if (selectionIdx == null) {
>					selectionIdx = String.valueOf(idx);
>				} else {
>					selectionIdx += "," + String.valueOf(idx);
>				}
>			}
>        	shellCaption += "; Selection: [" + selectionIdx + "]";
>		} else {
>			shellCaption += "; No selection";
>		}
>        table.getShell().setText(shellCaption);
>    }
>}

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Attachments on bug 235583: 103542 | 111652 | 111773