| /******************************************************************************* |
| * Copyright (c) 2008, 2016 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.examples.accessibility; |
| |
| import java.text.MessageFormat; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.ResourceBundle; |
| |
| import org.eclipse.swt.SWT; |
| import org.eclipse.swt.accessibility.ACC; |
| import org.eclipse.swt.accessibility.AccessibleAdapter; |
| import org.eclipse.swt.accessibility.AccessibleControlAdapter; |
| import org.eclipse.swt.accessibility.AccessibleControlEvent; |
| import org.eclipse.swt.accessibility.AccessibleEvent; |
| import org.eclipse.swt.events.FocusAdapter; |
| import org.eclipse.swt.events.FocusEvent; |
| import org.eclipse.swt.events.KeyAdapter; |
| import org.eclipse.swt.events.KeyEvent; |
| import org.eclipse.swt.events.MouseAdapter; |
| import org.eclipse.swt.events.MouseEvent; |
| import org.eclipse.swt.graphics.GC; |
| import org.eclipse.swt.graphics.Point; |
| import org.eclipse.swt.graphics.Rectangle; |
| import org.eclipse.swt.widgets.Canvas; |
| import org.eclipse.swt.widgets.Composite; |
| import org.eclipse.swt.widgets.Display; |
| |
| /** |
| * Instances of this class represent a very simple accessible bar chart. |
| * From an accessibility point of view, they present the data as a "list" with "list items". |
| */ |
| public class BarChart extends Canvas { |
| static ResourceBundle bundle = ResourceBundle.getBundle("examples_accessibility"); |
| List<Object[]> data = new ArrayList<>(); |
| String title; |
| int color = SWT.COLOR_RED; |
| int selectedItem = -1; |
| int valueMin = 0; |
| int valueMax = 10; |
| int valueIncrement = 1; |
| static final int GAP = 4; |
| static final int AXIS_WIDTH = 2; |
| |
| /** |
| * Constructs a new instance of this class given its parent |
| * and a style value describing its behavior and appearance. |
| * |
| * @param parent a composite control which will be the parent of the new instance (cannot be null) |
| * @param style the style of control to construct |
| */ |
| public BarChart(Composite parent, int style) { |
| super (parent, style); |
| |
| addListeners(); |
| } |
| |
| void addListeners() { |
| addPaintListener(e -> { |
| GC gc = e.gc; |
| Rectangle rect = getClientArea(); |
| Display display = getDisplay(); |
| int count = data.size(); |
| Point valueSize = gc.stringExtent (Integer.valueOf(valueMax).toString()); |
| int leftX = rect.x + 2 * GAP + valueSize.x; |
| int bottomY = rect.y + rect.height - 2 * GAP - valueSize.y; |
| int unitWidth = (rect.width - 4 * GAP - valueSize.x - AXIS_WIDTH) / count - GAP; |
| int unitHeight = (rect.height - 3 * GAP - AXIS_WIDTH - 2 * valueSize.y) / ((valueMax - valueMin) / valueIncrement); |
| // draw the title |
| int titleWidth = gc.stringExtent (title).x; |
| int center = (Math.max(titleWidth, count * (unitWidth + GAP) + GAP) - titleWidth) / 2; |
| gc.setForeground(display.getSystemColor(SWT.COLOR_BLACK)); |
| gc.drawString(title, leftX + AXIS_WIDTH + center, rect.y + GAP); |
| // draw the y axis and value labels |
| gc.setLineWidth(AXIS_WIDTH); |
| gc.drawLine(leftX, rect.y + GAP + valueSize.y, leftX, bottomY); |
| for (int i1 = valueMin; i1 <= valueMax; i1+=valueIncrement) { |
| int y = bottomY - i1 * unitHeight; |
| gc.drawLine(leftX, y, leftX - GAP, y); |
| gc.drawString(Integer.valueOf(i1).toString(), rect.x + GAP, y - valueSize.y); |
| } |
| // draw the x axis and item labels |
| gc.drawLine(leftX, bottomY, rect.x + rect.width - GAP, bottomY); |
| for (int i2 = 0; i2 < count; i2++) { |
| Object [] dataItem1 = data.get(i2); |
| String itemLabel = (String)dataItem1[0]; |
| int x1 = leftX + AXIS_WIDTH + GAP + i2 * (unitWidth + GAP); |
| gc.drawString(itemLabel, x1, bottomY + GAP); |
| } |
| // draw the bars |
| gc.setBackground(display.getSystemColor(color)); |
| for (int i3 = 0; i3 < count; i3++) { |
| Object [] dataItem2 = data.get(i3); |
| int itemValue1 = ((Integer)dataItem2[1]).intValue(); |
| int x2 = leftX + AXIS_WIDTH + GAP + i3 * (unitWidth + GAP); |
| gc.fillRectangle(x2, bottomY - AXIS_WIDTH - itemValue1 * unitHeight, unitWidth, itemValue1 * unitHeight); |
| } |
| if (isFocusControl()) { |
| if (selectedItem == -1) { |
| // draw the focus rectangle around the whole bar chart |
| gc.drawFocus(rect.x, rect.y, rect.width, rect.height); |
| } else { |
| // draw the focus rectangle around the selected item |
| Object [] dataItem3 = data.get(selectedItem); |
| int itemValue2 = ((Integer)dataItem3[1]).intValue(); |
| int x3 = leftX + AXIS_WIDTH + GAP + selectedItem * (unitWidth + GAP); |
| gc.drawFocus(x3, bottomY - itemValue2 * unitHeight - AXIS_WIDTH, unitWidth, itemValue2 * unitHeight + AXIS_WIDTH + GAP + valueSize.y); |
| } |
| } |
| }); |
| |
| addFocusListener(new FocusAdapter() { |
| @Override |
| public void focusGained(FocusEvent e) { |
| redraw(); |
| } |
| @Override |
| public void focusLost(FocusEvent e) { |
| redraw(); |
| } |
| }); |
| |
| addMouseListener(new MouseAdapter() { |
| @Override |
| public void mouseDown(MouseEvent e) { |
| if (getClientArea().contains(e.x, e.y)) { |
| setFocus(); |
| int item = -1; |
| int count = data.size(); |
| for (int i = 0; i < count; i++) { |
| if (itemBounds(i).contains(e.x, e.y)) { |
| item = i; |
| break; |
| } |
| } |
| if (item != selectedItem) { |
| selectedItem = item; |
| redraw(); |
| getAccessible().setFocus(item); |
| getAccessible().selectionChanged(); |
| } |
| } |
| } |
| }); |
| |
| addKeyListener(new KeyAdapter() { |
| @Override |
| public void keyPressed(KeyEvent e) { |
| boolean change = false; |
| switch (e.keyCode) { |
| case SWT.ARROW_DOWN: |
| case SWT.ARROW_RIGHT: |
| selectedItem++; |
| if (selectedItem >= data.size()) selectedItem = 0; |
| change = true; |
| break; |
| case SWT.ARROW_UP: |
| case SWT.ARROW_LEFT: |
| selectedItem--; |
| if (selectedItem <= -1) selectedItem = data.size() - 1; |
| change = true; |
| break; |
| case SWT.HOME: |
| selectedItem = 0; |
| change = true; |
| break; |
| case SWT.END: |
| selectedItem = data.size() - 1; |
| change = true; |
| break; |
| } |
| if (change) { |
| redraw(); |
| getAccessible().setFocus(selectedItem); |
| getAccessible().selectionChanged(); |
| } |
| } |
| }); |
| |
| addTraverseListener(e -> { |
| switch (e.detail) { |
| case SWT.TRAVERSE_TAB_NEXT: |
| case SWT.TRAVERSE_TAB_PREVIOUS: |
| e.doit = true; |
| break; |
| } |
| }); |
| |
| getAccessible().addAccessibleListener(new AccessibleAdapter() { |
| @Override |
| public void getName(AccessibleEvent e) { |
| MessageFormat formatter = new MessageFormat(""); //$NON_NLS$ |
| formatter.applyPattern(bundle.getString("name")); //$NON_NLS$ |
| int childID = e.childID; |
| if (childID == ACC.CHILDID_SELF) { |
| e.result = title; |
| } else { |
| Object [] item = data.get(childID); |
| e.result = formatter.format(item); |
| } |
| } |
| @Override |
| public void getDescription(AccessibleEvent e) { |
| int childID = e.childID; |
| if (childID != ACC.CHILDID_SELF) { |
| Object [] item = data.get(childID); |
| String value = item[1].toString(); |
| String colorName = bundle.getString("color" + color); //$NON_NLS$ |
| MessageFormat formatter = new MessageFormat(""); //$NON_NLS$ |
| formatter.applyPattern(bundle.getString("color_value")); //$NON_NLS$ |
| e.result = formatter.format(new String [] {colorName, value}); |
| } |
| } |
| }); |
| |
| getAccessible().addAccessibleControlListener(new AccessibleControlAdapter() { |
| @Override |
| public void getRole(AccessibleControlEvent e) { |
| if (e.childID == ACC.CHILDID_SELF) { |
| e.detail = ACC.ROLE_LIST; |
| } else { |
| e.detail = ACC.ROLE_LISTITEM; |
| } |
| } |
| @Override |
| public void getChildCount(AccessibleControlEvent e) { |
| e.detail = data.size(); |
| } |
| @Override |
| public void getChildren(AccessibleControlEvent e) { |
| int count = data.size(); |
| Object[] children = new Object[count]; |
| for (int i = 0; i < count; i++) { |
| children[i] = Integer.valueOf(i); |
| } |
| e.children = children; |
| } |
| @Override |
| public void getChildAtPoint(AccessibleControlEvent e) { |
| Point testPoint = toControl(e.x, e.y); |
| int childID = ACC.CHILDID_NONE; |
| if (getClientArea().contains(testPoint)) { |
| childID = ACC.CHILDID_SELF; |
| int count = data.size(); |
| for (int i = 0; i < count; i++) { |
| if (itemBounds(i).contains(testPoint)) { |
| childID = i; |
| break; |
| } |
| } |
| } |
| e.childID = childID; |
| } |
| @Override |
| public void getLocation(AccessibleControlEvent e) { |
| Rectangle location = null; |
| Point pt = null; |
| int childID = e.childID; |
| if (childID == ACC.CHILDID_SELF) { |
| location = getClientArea(); |
| pt = getParent().toDisplay(location.x, location.y); |
| } else { |
| location = itemBounds(childID); |
| pt = toDisplay(location.x, location.y); |
| } |
| e.x = pt.x; |
| e.y = pt.y; |
| e.width = location.width; |
| e.height = location.height; |
| } |
| @Override |
| public void getFocus(AccessibleControlEvent e) { |
| int childID = ACC.CHILDID_NONE; |
| if (isFocusControl()) { |
| if (selectedItem == -1) { |
| childID = ACC.CHILDID_SELF; |
| } else { |
| childID = selectedItem; |
| } |
| } |
| e.childID = childID; |
| |
| } |
| @Override |
| public void getSelection(AccessibleControlEvent e) { |
| e.childID = (selectedItem == -1) ? ACC.CHILDID_NONE : selectedItem; |
| } |
| @Override |
| public void getValue(AccessibleControlEvent e) { |
| int childID = e.childID; |
| if (childID != ACC.CHILDID_SELF) { |
| Object [] dataItem = data.get(childID); |
| e.result = ((Integer)dataItem[1]).toString(); |
| } |
| } |
| @Override |
| public void getState(AccessibleControlEvent e) { |
| int childID = e.childID; |
| e.detail = ACC.STATE_FOCUSABLE; |
| if (isFocusControl()) e.detail |= ACC.STATE_FOCUSED; |
| if (childID != ACC.CHILDID_SELF) { |
| e.detail |= ACC.STATE_SELECTABLE; |
| if (childID == selectedItem) e.detail |= ACC.STATE_SELECTED; |
| } |
| } |
| }); |
| } |
| |
| @Override |
| public Point computeSize (int wHint, int hHint, boolean changed) { |
| checkWidget (); |
| int count = data.size(); |
| GC gc = new GC (this); |
| int titleWidth = gc.stringExtent (title).x; |
| Point valueSize = gc.stringExtent (Integer.valueOf(valueMax).toString()); |
| int itemWidth = 0; |
| for (int i = 0; i < count; i++) { |
| Object [] dataItem = data.get(i); |
| String itemLabel = (String)dataItem[0]; |
| itemWidth = Math.max(itemWidth, gc.stringExtent (itemLabel).x); |
| } |
| gc.dispose(); |
| int width = Math.max(titleWidth, count * (itemWidth + GAP) + GAP) + 3 * GAP + AXIS_WIDTH + valueSize.x; |
| int height = 3 * GAP + AXIS_WIDTH + valueSize.y * ((valueMax - valueMin) / valueIncrement + 3); |
| if (wHint != SWT.DEFAULT) width = wHint; |
| if (hHint != SWT.DEFAULT) height = hHint; |
| int border = getBorderWidth (); |
| Rectangle trim = computeTrim (0, 0, width + border*2, height + border*2); |
| return new Point (trim.width, trim.height); |
| } |
| |
| /** |
| * Add a labeled data value to the bar chart. |
| * |
| * @param label a string describing the value |
| * @param value the data value |
| */ |
| public void addData (String label, int value) { |
| checkWidget (); |
| data.add(new Object[] {label, Integer.valueOf(value)}); |
| } |
| |
| /** |
| * Set the title of the bar chart. |
| * |
| * @param title a string to display as the bar chart's title. |
| */ |
| public void setTitle (String title) { |
| checkWidget (); |
| this.title = title; |
| } |
| |
| /** |
| * Set the bar color to the specified color. |
| * The default color is SWT.COLOR_RED. |
| * |
| * @param color any of the SWT.COLOR_* constants |
| */ |
| public void setColor (int color) { |
| checkWidget (); |
| this.color = color; |
| } |
| |
| /** |
| * Set the minimum value for the y axis. |
| * The default minimum is 0. |
| * |
| * @param min the minimum value |
| */ |
| public void setValueMin (int min) { |
| checkWidget (); |
| valueMin = min; |
| } |
| |
| /** |
| * Set the maximum value for the y axis. |
| * The default maximum is 10. |
| * |
| * @param max the maximum value |
| */ |
| public void setValueMax (int max) { |
| checkWidget (); |
| valueMax = max; |
| } |
| |
| /** |
| * Set the increment value for the y axis. |
| * The default increment is 1. |
| * |
| * @param increment the increment value |
| */ |
| public void setValueIncrement (int increment) { |
| checkWidget (); |
| valueIncrement = increment; |
| } |
| |
| /* The bounds of the specified item in the coordinate system of the BarChart. */ |
| Rectangle itemBounds(int index) { |
| Rectangle rect = getClientArea(); |
| GC gc = new GC (BarChart.this); |
| Point valueSize = gc.stringExtent (Integer.valueOf(valueMax).toString()); |
| gc.dispose(); |
| int leftX = rect.x + 2 * GAP + valueSize.x; |
| int bottomY = rect.y + rect.height - 2 * GAP - valueSize.y; |
| int unitWidth = (rect.width - 4 * GAP - valueSize.x - AXIS_WIDTH) / data.size() - GAP; |
| int unitHeight = (rect.height - 3 * GAP - AXIS_WIDTH - 2 * valueSize.y) / ((valueMax - valueMin) / valueIncrement); |
| Object [] dataItem = data.get(index); |
| int itemValue = ((Integer)dataItem[1]).intValue(); |
| int x = leftX + AXIS_WIDTH + GAP + index * (unitWidth + GAP); |
| return new Rectangle(x, bottomY - itemValue * unitHeight - AXIS_WIDTH, unitWidth, itemValue * unitHeight + AXIS_WIDTH + GAP + valueSize.y); |
| } |
| } |