1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.swing.plaf;
27
28 import javax.swing.JComponent;
29 import javax.swing.SwingUtilities;
30 import javax.accessibility.Accessible;
31
32 import java.awt.Component;
33 import java.awt.Container;
34 import java.awt.Dimension;
35 import java.awt.Graphics;
36 import java.awt.Insets;
37
38
39 /**
40 * The base class for all UI delegate objects in the Swing pluggable
41 * look and feel architecture. The UI delegate object for a Swing
42 * component is responsible for implementing the aspects of the
43 * component that depend on the look and feel.
44 * The <code>JComponent</code> class
45 * invokes methods from this class in order to delegate operations
46 * (painting, layout calculations, etc.) that may vary depending on the
47 * look and feel installed. <b>Client programs should not invoke methods
48 * on this class directly.</b>
49 *
50 * @see javax.swing.JComponent
51 * @see javax.swing.UIManager
52 *
53 */
54 public abstract class ComponentUI {
55 /**
56 * Sole constructor. (For invocation by subclass constructors,
57 * typically implicit.)
58 */
59 public ComponentUI() {
60 }
61
62 /**
63 * Configures the specified component appropriately for the look and feel.
64 * This method is invoked when the <code>ComponentUI</code> instance is being installed
65 * as the UI delegate on the specified component. This method should
66 * completely configure the component for the look and feel,
67 * including the following:
68 * <ol>
69 * <li>Install default property values for color, fonts, borders,
70 * icons, opacity, etc. on the component. Whenever possible,
71 * property values initialized by the client program should <i>not</i>
72 * be overridden.
73 * <li>Install a <code>LayoutManager</code> on the component if necessary.
74 * <li>Create/add any required sub-components to the component.
75 * <li>Create/install event listeners on the component.
76 * <li>Create/install a <code>PropertyChangeListener</code> on the component in order
77 * to detect and respond to component property changes appropriately.
78 * <li>Install keyboard UI (mnemonics, traversal, etc.) on the component.
79 * <li>Initialize any appropriate instance data.
80 * </ol>
81 * @param c the component where this UI delegate is being installed
82 *
83 * @see #uninstallUI
84 * @see javax.swing.JComponent#setUI
85 * @see javax.swing.JComponent#updateUI
86 */
87 public void installUI(JComponent c) {
88 }
89
90 /**
91 * Reverses configuration which was done on the specified component during
92 * <code>installUI</code>. This method is invoked when this
93 * <code>UIComponent</code> instance is being removed as the UI delegate
94 * for the specified component. This method should undo the
95 * configuration performed in <code>installUI</code>, being careful to
96 * leave the <code>JComponent</code> instance in a clean state (no
97 * extraneous listeners, look-and-feel-specific property objects, etc.).
98 * This should include the following:
99 * <ol>
100 * <li>Remove any UI-set borders from the component.
101 * <li>Remove any UI-set layout managers on the component.
102 * <li>Remove any UI-added sub-components from the component.
103 * <li>Remove any UI-added event/property listeners from the component.
104 * <li>Remove any UI-installed keyboard UI from the component.
105 * <li>Nullify any allocated instance data objects to allow for GC.
106 * </ol>
107 * @param c the component from which this UI delegate is being removed;
108 * this argument is often ignored,
109 * but might be used if the UI object is stateless
110 * and shared by multiple components
111 *
112 * @see #installUI
113 * @see javax.swing.JComponent#updateUI
114 */
115 public void uninstallUI(JComponent c) {
116 }
117
118 /**
119 * Paints the specified component appropriately for the look and feel.
120 * This method is invoked from the <code>ComponentUI.update</code> method when
121 * the specified component is being painted. Subclasses should override
122 * this method and use the specified <code>Graphics</code> object to
123 * render the content of the component.
124 *
125 * @param g the <code>Graphics</code> context in which to paint
126 * @param c the component being painted;
127 * this argument is often ignored,
128 * but might be used if the UI object is stateless
129 * and shared by multiple components
130 *
131 * @see #update
132 */
133 public void paint(Graphics g, JComponent c) {
134 }
135
348 /**
349 * Returns the <code>i</code>th <code>Accessible</code> child of the object.
350 * UIs might need to override this if they present areas on the
351 * screen that can be viewed as components, but actual components
352 * are not used for presenting those areas.
353 *
354 * <p>
355 *
356 * Note: As of v1.3, it is recommended that developers call
357 * <code>Component.AccessibleAWTComponent.getAccessibleChild()</code> instead of
358 * this method.
359 *
360 * @param c a {@code JComponent} for which to get a child object
361 * @param i zero-based index of child
362 * @return the <code>i</code>th <code>Accessible</code> child of the object
363 * @see #getAccessibleChildrenCount
364 */
365 public Accessible getAccessibleChild(JComponent c, int i) {
366 return SwingUtilities.getAccessibleChild(c, i);
367 }
368 }
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1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.swing.plaf;
27
28 import javax.swing.JComponent;
29 import javax.swing.SwingUtilities;
30 import javax.accessibility.Accessible;
31
32 import java.awt.Component;
33 import java.awt.Dimension;
34 import java.awt.Graphics;
35 import javax.swing.UIManager;
36 import sun.swing.SwingUtilities2;
37
38
39 /**
40 * The base class for all UI delegate objects in the Swing pluggable
41 * look and feel architecture. The UI delegate object for a Swing
42 * component is responsible for implementing the aspects of the
43 * component that depend on the look and feel.
44 * The <code>JComponent</code> class
45 * invokes methods from this class in order to delegate operations
46 * (painting, layout calculations, etc.) that may vary depending on the
47 * look and feel installed. <b>Client programs should not invoke methods
48 * on this class directly.</b>
49 *
50 * @see javax.swing.JComponent
51 * @see javax.swing.UIManager
52 *
53 */
54 public abstract class ComponentUI {
55
56 private TextUIDrawing textUIDrawing;
57
58 /**
59 * Sole constructor. (For invocation by subclass constructors,
60 * typically implicit.)
61 */
62 public ComponentUI() {
63 }
64
65 /**
66 * Configures the specified component appropriately for the look and feel.
67 * This method is invoked when the <code>ComponentUI</code> instance is being installed
68 * as the UI delegate on the specified component. This method should
69 * completely configure the component for the look and feel,
70 * including the following:
71 * <ol>
72 * <li>Install default property values for color, fonts, borders,
73 * icons, opacity, etc. on the component. Whenever possible,
74 * property values initialized by the client program should <i>not</i>
75 * be overridden.
76 * <li>Install a <code>LayoutManager</code> on the component if necessary.
77 * <li>Create/add any required sub-components to the component.
78 * <li>Create/install event listeners on the component.
79 * <li>Create/install a <code>PropertyChangeListener</code> on the component in order
80 * to detect and respond to component property changes appropriately.
81 * <li>Install keyboard UI (mnemonics, traversal, etc.) on the component.
82 * <li>Initialize any appropriate instance data.
83 * </ol>
84 * @param c the component where this UI delegate is being installed
85 *
86 * @see #uninstallUI
87 * @see javax.swing.JComponent#setUI
88 * @see javax.swing.JComponent#updateUI
89 */
90 public void installUI(JComponent c) {
91
92 if (textUIDrawing == null || textUIDrawing instanceof UIResource) {
93 textUIDrawing = (TextUIDrawing) UIManager.get("uiDrawing.text");
94 }
95
96 if (textUIDrawing == null) {
97 textUIDrawing = SwingUtilities2.DEFAULT_UI_TEXT_DRAWING;
98 }
99 }
100
101 /**
102 * Reverses configuration which was done on the specified component during
103 * <code>installUI</code>. This method is invoked when this
104 * <code>UIComponent</code> instance is being removed as the UI delegate
105 * for the specified component. This method should undo the
106 * configuration performed in <code>installUI</code>, being careful to
107 * leave the <code>JComponent</code> instance in a clean state (no
108 * extraneous listeners, look-and-feel-specific property objects, etc.).
109 * This should include the following:
110 * <ol>
111 * <li>Remove any UI-set borders from the component.
112 * <li>Remove any UI-set layout managers on the component.
113 * <li>Remove any UI-added sub-components from the component.
114 * <li>Remove any UI-added event/property listeners from the component.
115 * <li>Remove any UI-installed keyboard UI from the component.
116 * <li>Nullify any allocated instance data objects to allow for GC.
117 * </ol>
118 * @param c the component from which this UI delegate is being removed;
119 * this argument is often ignored,
120 * but might be used if the UI object is stateless
121 * and shared by multiple components
122 *
123 * @see #installUI
124 * @see javax.swing.JComponent#updateUI
125 */
126 public void uninstallUI(JComponent c) {
127 if (textUIDrawing instanceof UIResource) {
128 textUIDrawing = null;
129 }
130 }
131
132 /**
133 * Paints the specified component appropriately for the look and feel.
134 * This method is invoked from the <code>ComponentUI.update</code> method when
135 * the specified component is being painted. Subclasses should override
136 * this method and use the specified <code>Graphics</code> object to
137 * render the content of the component.
138 *
139 * @param g the <code>Graphics</code> context in which to paint
140 * @param c the component being painted;
141 * this argument is often ignored,
142 * but might be used if the UI object is stateless
143 * and shared by multiple components
144 *
145 * @see #update
146 */
147 public void paint(Graphics g, JComponent c) {
148 }
149
362 /**
363 * Returns the <code>i</code>th <code>Accessible</code> child of the object.
364 * UIs might need to override this if they present areas on the
365 * screen that can be viewed as components, but actual components
366 * are not used for presenting those areas.
367 *
368 * <p>
369 *
370 * Note: As of v1.3, it is recommended that developers call
371 * <code>Component.AccessibleAWTComponent.getAccessibleChild()</code> instead of
372 * this method.
373 *
374 * @param c a {@code JComponent} for which to get a child object
375 * @param i zero-based index of child
376 * @return the <code>i</code>th <code>Accessible</code> child of the object
377 * @see #getAccessibleChildrenCount
378 */
379 public Accessible getAccessibleChild(JComponent c, int i) {
380 return SwingUtilities.getAccessibleChild(c, i);
381 }
382
383 /**
384 * Returns the {@code TextUIDrawing} instance responsible for text drawing
385 * and measuring.
386 *
387 * @return {@code TextUIDrawing} instance
388 *
389 * @since 9
390 */
391 public TextUIDrawing getTextUIDrawing() {
392 return textUIDrawing;
393 }
394 }
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