1 /*
2 * Copyright (c) 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 java.awt.FontMetrics;
29 import java.awt.Graphics;
30 import javax.swing.JComponent;
31
32 /**
33 * This interface is designed to be used by various component ui classes
34 * for drawing and measuring text.
35 * {@literal L&F} sets the instance of the {@code TextUIDrawing} to the
36 * look and feel defaults using {@literal "uiDrawing.text"} property.
37 * To get an instance of {@code TextUIDrawing} for the current {@literal L&F}
38 * use {@code UIManager.get("uiDrawing.text")}.
39 * To set a custom {@code TextUIDrawing} use
40 * {@code UIManager.put("uiDrawing.text", new CustomTextUIDrawing())}.
41 *
42 * @since 9
43 */
44 public interface TextUIDrawing {
45 /**
46 * Draws the given string at the specified location.
47 * Nothing is drawn for the null string.
48 *
49 * @param c the component that will display the string, may be null
50 * @param g the graphics context, must not be null
51 * @param string the string to display, may be null
52 * @param x the x coordinate to draw the text at
53 * @param y the y coordinate to draw the text at
54 * @throws NullPointerException if the specified {@code g} is {@code null}
55 *
56 * @since 9
57 */
58 void drawString(JComponent c, Graphics g, String string, int x, int y);
59
60 /**
61 * Draws the given string at the specified location underlining
62 * the specified character.
63 * <p>
64 * The underline will be positioned at the base glyph which represents
65 * the valid char indicated by the index. If the char index is not valid
66 * or is not the index of a valid unicode code point then no underline
67 * is drawn.
68 *
69 * @param c the component that will display the string, may be null
70 * @param g the graphics context, must not be null
71 * @param string the string to display, may be null
72 * @param underlinedIndex index of a a char value (Unicode code unit)
73 * in the string to underline
74 * @param x the x coordinate to draw the text at
75 * @param y the y coordinate to draw the text at
76 * @throws NullPointerException if the specified {@code g} is {@code null}
77 *
78 * @see #getStringWidth
79 *
80 * @since 9
81 */
82 void drawStringUnderlineCharAt(JComponent c, Graphics g,
83 String string, int underlinedIndex,
84 int x, int y);
85
86 /**
87 * Clips the passed in string to the space provided.
88 *
89 * @param c the component
90 * @param fm the FontMetrics used to measure the string width, must be
91 * obtained from the correct font and graphics. Must not be null.
92 * @param string the string to clip, may be null
93 * @param availTextWidth the amount of space that the string can be drawn in
94 * @return the clipped string that fits in the provided space, an empty
95 * string if the given string argument is {@code null} or empty
96 * @throws NullPointerException if the specified {@code fm} is {@code null}
97 *
98 * @see #getStringWidth
99 *
100 * @since 9
101 */
102 String getClippedString(JComponent c, FontMetrics fm, String string,
103 int availTextWidth);
104 /**
105 * Returns the total advance width of the passed in string.
106 * The advance is the distance from the leftmost point to the rightmost point
107 * on the string's baseline.
108 * If the passed string is {@code null}, returns zero.
109 *
110 * @param c the component, may be null
111 * @param fm the FontMetrics used to measure the advance string width, must
112 * be obtained from the correct font and graphics. Must not be null.
113 * @param string the string to get the advance width of, may be null
114 * @return the advance width of the specified string, zero is returned for
115 * {@code null} string
116 * @throws NullPointerException if the specified {@code fm} is {@code null}
117 *
118 * @since 9
119 */
120 int getStringWidth(JComponent c, FontMetrics fm, String string);
121 }