1 /*
2 * Copyright 2006-2016 The JGUIraffe Team.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License")
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package net.sf.jguiraffe.gui.layout;
17
18 /**
19 * <p>
20 * Definition of an interface for performing size calculations in a manner
21 * independent of a certain component model.
22 * </p>
23 * <p>
24 * This interface is used by the {@code Unit} class to perform unit to pixel
25 * calculations. For some unit types access to certain internal details of the
26 * affected components is needed, e.g. to the font for determining the font
27 * size. This interface has the purpose of abstracting such direct accesses, so
28 * that there can be multiple implementations for different GUI libraries (e.g.
29 * Swing and SWT).
30 * </p>
31 *
32 * @author Oliver Heger
33 * @version $Id: UnitSizeHandler.java 205 2012-01-29 18:29:57Z oheger $
34 */
35 public interface UnitSizeHandler
36 {
37 /**
38 * Determines the font size of the given component for the specified
39 * orientation. An implementation must extract the font of the passed in
40 * component (after it has been correctly casted) and then determine the
41 * average font size either in X- or Y-direction.
42 *
43 * @param component the component
44 * @param y the orientation flag ( <b>true</b> for Y or vertical,
45 * <b>false</b> for X or horizontal
46 * @return the font size
47 */
48 double getFontSize(Object component, boolean y);
49
50 /**
51 * Returns the screen resolution in dots per inch (dpi).
52 *
53 * @return the screen resolution in dpi
54 */
55 int getScreenResolution();
56 }