Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2018 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.swt.examples.layoutexample; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.CCombo; import org.eclipse.swt.custom.StackLayout; import org.eclipse.swt.custom.TableEditor; import org.eclipse.swt.events.MouseListener; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Group; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Spinner; import org.eclipse.swt.widgets.TableItem; import org.eclipse.swt.widgets.Text; class StackLayoutTab extends Tab { /* Controls for setting layout parameters */ Button backButton, advanceButton; Label topControl; Spinner marginWidth, marginHeight; /* The example layout instance */ StackLayout stackLayout; int currentLayer = -1; /* TableEditors and related controls*/ TableEditor comboEditor, nameEditor; CCombo combo; Text nameText; final int NAME_COL = 0; final int TOTAL_COLS = 2; /** * Creates the Tab within a given instance of LayoutExample. */ StackLayoutTab(LayoutExample instance) { super(instance); } /** * Creates the widgets in the "child" group. */ @Override void createChildWidgets() { /* Add common controls */ super.createChildWidgets(); /* Add TableEditors */ comboEditor = new TableEditor(table); nameEditor = new TableEditor(table); table.addMouseListener(MouseListener.mouseDownAdapter(e -> { resetEditors(); index = table.getSelectionIndex(); if (index == -1) return; // set top layer of stack to the selected item setTopControl(index); TableItem oldItem = comboEditor.getItem(); newItem = table.getItem(index); if (newItem == oldItem || newItem != lastSelected) { lastSelected = newItem; return; } table.showSelection(); combo = new CCombo(table, SWT.READ_ONLY); createComboEditor(combo, comboEditor); nameText = new Text(table, SWT.SINGLE); nameText.setText(data.get(index)[NAME_COL]); createTextEditor(nameText, nameEditor, NAME_COL); })); } /** * Creates the control widgets. */ @Override void createControlWidgets() { /* Controls the topControl in the StackLayout */ Group columnGroup = new Group(controlGroup, SWT.NONE); columnGroup.setText("topControl");//(LayoutExample.getResourceString ("Top_Control")); columnGroup.setLayout(new GridLayout(3, false)); columnGroup.setLayoutData(new GridData(SWT.FILL, SWT.FILL, false, false)); backButton = new Button(columnGroup, SWT.PUSH); backButton.setText("<<"); backButton.setEnabled(false); backButton.setLayoutData(new GridData(SWT.END, SWT.CENTER, false, false)); backButton.addSelectionListener( SelectionListener.widgetSelectedAdapter(e -> setTopControl(currentLayer - 1))); topControl = new Label(columnGroup, SWT.BORDER); topControl.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false)); advanceButton = new Button(columnGroup, SWT.PUSH); advanceButton.setText(">>"); advanceButton.setEnabled(false); advanceButton.addSelectionListener( SelectionListener.widgetSelectedAdapter(e -> setTopControl(currentLayer + 1))); /* Controls the margins of the StackLayout */ Group marginGroup = new Group(controlGroup, SWT.NONE); marginGroup.setText(LayoutExample.getResourceString("Margins")); marginGroup.setLayout(new GridLayout(2, false)); marginGroup.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false)); new Label(marginGroup, SWT.NONE).setText("marginWidth"); marginWidth = new Spinner(marginGroup, SWT.BORDER); marginWidth.setSelection(0); marginWidth.addSelectionListener(selectionListener); new Label(marginGroup, SWT.NONE).setText("marginHeight"); marginHeight = new Spinner(marginGroup, SWT.BORDER); marginHeight.setSelection(0); marginHeight.setLayoutData(new GridData(SWT.BEGINNING, SWT.CENTER, false, false)); marginHeight.addSelectionListener(selectionListener); /* Add common controls */ super.createControlWidgets(); } /** * Creates the example layout. */ @Override void createLayout() { stackLayout = new StackLayout(); layoutComposite.setLayout(stackLayout); } @Override void createLayoutComposite() { layoutComposite = new Composite(layoutGroup, SWT.BORDER); layoutComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1)); createLayout(); } /** * Disposes the editors without placing their contents * into the table. */ @Override void disposeEditors() { comboEditor.setEditor(null, null, -1); combo.dispose(); nameText.dispose(); } /** * Generates code for the example layout. */ @Override StringBuilder generateLayoutCode() { StringBuilder code = new StringBuilder(); code.append("\t\tStackLayout stackLayout = new StackLayout ();\n"); if (stackLayout.marginWidth != 0) { code.append("\t\tstackLayout.marginWidth = " + stackLayout.marginWidth + ";\n"); } if (stackLayout.marginHeight != 0) { code.append("\t\tstackLayout.marginHeight = " + stackLayout.marginHeight + ";\n"); } code.append("\t\tshell.setLayout (stackLayout);\n"); for (int i = 0; i < children.length; i++) { Control control = children[i]; code.append(getChildCode(control, i)); } if (children.length > 0 && currentLayer != -1) { code.append("\n\t\tstackLayout.topControl = " + names[currentLayer] + ";\n"); } return code; } @Override boolean needsCustom() { return true; } /** * Returns the string to insert when a new child control is added to the table. */ @Override String[] getInsertString(String name, String controlType) { return new String[] { name, controlType }; } /** * Returns the layout data field names. */ @Override String[] getLayoutDataFieldNames() { return new String[] { "Control Name", "Control Type" }; } /** * Gets the text for the tab folder item. */ @Override String getTabText() { return "StackLayout"; } /** * Takes information from TableEditors and stores it. */ @Override void resetEditors(boolean tab) { TableItem oldItem = comboEditor.getItem(); comboEditor.setEditor(null, null, -1); if (oldItem != null) { int row = table.indexOf(oldItem); try { new String(nameText.getText()); } catch (NumberFormatException e) { nameText.setText(oldItem.getText(NAME_COL)); } String[] insert = new String[] { nameText.getText(), combo.getText() }; data.set(row, insert); for (int i = 0; i < TOTAL_COLS; i++) { oldItem.setText(i, data.get(row)[i]); } if (!tab) disposeEditors(); } setLayoutState(); refreshLayoutComposite(); setTopControl(currentLayer); layoutGroup.layout(true); } void setTopControl(int index) { if (index == -1 || children.length == 0) { currentLayer = -1; topControl.setText(""); } else { currentLayer = index; stackLayout.topControl = children[currentLayer]; layoutComposite.layout(); TableItem item = table.getItem(currentLayer); topControl.setText(item.getText(0)); } backButton.setEnabled(children.length > 1 && currentLayer > 0); advanceButton.setEnabled(children.length > 1 && currentLayer < children.length - 1); } /** * Sets the state of the layout. */ @Override void setLayoutState() { /* Set the margins and spacing */ stackLayout.marginWidth = marginWidth.getSelection(); stackLayout.marginHeight = marginHeight.getSelection(); } }