001/*
002 * Copyright (c) 2002-2007 JGoodies Karsten Lentzsch. All Rights Reserved.
003 *
004 * Redistribution and use in source and binary forms, with or without
005 * modification, are permitted provided that the following conditions are met:
006 *
007 *  o Redistributions of source code must retain the above copyright notice,
008 *    this list of conditions and the following disclaimer.
009 *
010 *  o Redistributions in binary form must reproduce the above copyright notice,
011 *    this list of conditions and the following disclaimer in the documentation
012 *    and/or other materials provided with the distribution.
013 *
014 *  o Neither the name of JGoodies Karsten Lentzsch nor the names of
015 *    its contributors may be used to endorse or promote products derived
016 *    from this software without specific prior written permission.
017 *
018 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
019 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
020 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
021 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
022 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
023 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
024 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
025 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
026 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
027 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
028 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030
031package com.jgoodies.forms.util;
032
033import java.util.logging.Logger;
034
035import com.jgoodies.forms.layout.ConstantSize;
036import com.jgoodies.forms.layout.Size;
037
038/**
039 * An abstract class that describes a layout and design style guide.
040 * It provides constants used to lay out panels consistently.<p>
041 *
042 * This class is work in progress and the API may change without notice.
043 * Therefore it is recommended to not write custom subclasses
044 * for production code.
045 * A future version of this class will likely collaborate with a class
046 * <code>LogicalSize</code> or <code>StyledSize</code>.
047 *
048 * @author Karsten Lentzsch
049 * @version $Revision$
050 *
051 * @see com.jgoodies.forms.util.MacLayoutStyle
052 * @see com.jgoodies.forms.util.WindowsLayoutStyle
053 * @see com.jgoodies.forms.factories.FormFactory
054 * @see com.jgoodies.forms.factories.Borders
055 */
056
057public abstract class LayoutStyle {
058
059    /**
060     * Holds the current layout style.
061     */
062    private static LayoutStyle current = initialLayoutStyle();
063
064    // Computing the initial layout style *************************************
065
066    /**
067     * Computes and returns the initial <code>LayoutStyle</code>.
068     * Checks the OS name and returns <code>MacLayoutStyle</code>
069     * on Mac OS X and <code>WindowLayoutStyle</code> on all other platforms.
070     *
071     * @return MacLayoutStyle on Mac, WindowsLayoutStyle on all other platforms
072     */
073    private static LayoutStyle initialLayoutStyle() {
074        if (isOSMac()) {
075            return MacLayoutStyle.INSTANCE;
076        }
077        return WindowsLayoutStyle.INSTANCE;
078    }
079
080    /**
081     * Checks and answers whether Java runs on a Mac by requesting
082     * the system property <em>os.name</em>.
083     *
084     * @return true on Mac, false on all other Platforms
085     */
086    private static boolean isOSMac() {
087        return getSystemProperty("os.name").startsWith("Mac");
088    }
089
090    /**
091     * Tries to look up the System property for the given key.
092     * In untrusted environments this may throw a SecurityException.
093     * In this case we catch the exception and answer <code>null</code>.
094     *
095     * @param key   the name of the system property
096     * @return the system property's String value, or a blank string
097     *     if there's no such value, or a SecurityException has been caught.
098     */
099    private static String getSystemProperty(String key) {
100        try {
101            return System.getProperty(key);
102        } catch (SecurityException e) {
103            Logger.getLogger(LayoutStyle.class.getName())
104                    .warning("Can't read the System property " + key + ".");
105            return "";
106        }
107    }
108
109    // Accessing the current style ******************************************
110
111    /**
112     * Returns the current <code>LayoutStyle</code>.
113     *
114     * @return the current <code>LayoutStyle</code>
115     */
116    public static LayoutStyle getCurrent() {
117        return current;
118    }
119
120    /**
121     * Set a new <code>LayoutStyle</code>.
122     *
123     * @param newLayoutStyle   the style to be set
124     */
125    public static void setCurrent(LayoutStyle newLayoutStyle) {
126        current = newLayoutStyle;
127    }
128
129    // Layout Sizes *********************************************************
130
131    /**
132     * Returns this style's default button width.
133     *
134     * @return the default button width
135     *
136     * @see #getDefaultButtonHeight()
137     */
138    public abstract Size getDefaultButtonWidth();
139
140    /**
141     * Returns this style's default button height.
142     *
143     * @return the default button height
144     *
145     * @see #getDefaultButtonWidth()
146     */
147    public abstract Size getDefaultButtonHeight();
148
149    /**
150     * Returns this style's horizontal margin for general dialogs.
151     *
152     * @return the horizontal margin for general dialogs
153     *
154     * @see #getDialogMarginY()
155     * @see #getTabbedDialogMarginX()
156     */
157    public abstract ConstantSize getDialogMarginX();
158
159    /**
160     * Returns this style's vertical margin for general dialogs.
161     *
162     * @return the vertical margin for general dialogs
163     *
164     * @see #getDialogMarginX()
165     * @see #getTabbedDialogMarginY()
166     */
167    public abstract ConstantSize getDialogMarginY();
168
169    /**
170     * Returns this style's horizontal margin for dialogs that consist of
171     * a tabbed pane.
172     *
173     * @return the horizontal margin for dialogs that consist of a tabbed pane
174     * @since 1.0.3
175     *
176     * @see #getTabbedDialogMarginY()
177     * @see #getDialogMarginX()
178     */
179    public abstract ConstantSize getTabbedDialogMarginX();
180
181    /**
182     * Returns this style's vertical margin for dialogs that consist of
183     * a tabbed pane.
184     *
185     * @return the vertical margin for dialogs that consist of a tabbed pane
186     * @since 1.0.3
187     *
188     * @see #getTabbedDialogMarginX()
189     * @see #getDialogMarginY()
190     */
191    public abstract ConstantSize getTabbedDialogMarginY();
192
193    /**
194     * Returns a gap used to separate a label and associated control.
195     *
196     * @return a gap between label and associated control
197     *
198     * @see #getRelatedComponentsPadX()
199     * @see #getUnrelatedComponentsPadX()
200     */
201    public abstract ConstantSize getLabelComponentPadX();
202
203    /**
204     * Returns a horizontal gap used to separate related controls.
205     *
206     * @return a horizontal gap between related controls
207     *
208     * @see #getLabelComponentPadX()
209     * @see #getRelatedComponentsPadY()
210     * @see #getUnrelatedComponentsPadX()
211     */
212    public abstract ConstantSize getRelatedComponentsPadX();
213
214    /**
215     * Returns a vertical gap used to separate related controls.
216     *
217     * @return a vertical gap between related controls
218     *
219     * @see #getRelatedComponentsPadX()
220     * @see #getUnrelatedComponentsPadY()
221     */
222    public abstract ConstantSize getRelatedComponentsPadY();
223
224    /**
225     * Returns a horizontal gap used to separate unrelated controls.
226     *
227     * @return a horizontal gap between unrelated controls
228     *
229     * @see #getLabelComponentPadX()
230     * @see #getUnrelatedComponentsPadY()
231     * @see #getRelatedComponentsPadX()
232     */
233    public abstract ConstantSize getUnrelatedComponentsPadX();
234
235    /**
236     * Returns a vertical gap used to separate unrelated controls.
237     *
238     * @return a vertical gap between unrelated controls
239     *
240     * @see #getUnrelatedComponentsPadX()
241     * @see #getRelatedComponentsPadY()
242     */
243    public abstract ConstantSize getUnrelatedComponentsPadY();
244
245    /**
246     * Returns a narrow vertical pad used to separate lines.
247     *
248     * @return a narrow vertical pad used to separate lines
249     *
250     * @see #getLinePad()
251     * @see #getParagraphPad()
252     */
253    public abstract ConstantSize getNarrowLinePad();
254
255    /**
256     * Returns a narrow vertical pad used to separate lines.
257     *
258     * @return a vertical pad used to separate lines
259     *
260     * @see #getNarrowLinePad()
261     * @see #getParagraphPad()
262     */
263    public abstract ConstantSize getLinePad();
264
265    /**
266     * Returns a pad used to separate paragraphs.
267     *
268     * @return a vertical pad used to separate paragraphs
269     *
270     * @see #getNarrowLinePad()
271     * @see #getLinePad()
272     */
273    public abstract ConstantSize getParagraphPad();
274
275    /**
276     * Returns a pad used to separate a button bar from a component.
277     *
278     * @return a vertical pad used to separate paragraphs
279     * @since 1.0.3
280     *
281     * @see #getRelatedComponentsPadY()
282     * @see #getUnrelatedComponentsPadY()
283     */
284    public abstract ConstantSize getButtonBarPad();
285
286    /**
287     * Checks and answers whether buttons are typically ordered from
288     * left to right or from right to left. Useful for building button bars
289     * that shall comply with the platform's layout style guide.<p>
290     *
291     * For example the Windows style guide recommends to layout out
292     * <em>OK, Cancel, Apply</em> from left to right, where the
293     * Mac Aqua style guide recommends to layout out these buttons
294     * from right to left.<p>
295     *
296     * Although most button sequences shall honor this order
297     * some buttons require a left to right order. For example
298     * <em>Back, Next</em> or <em>Move Left, Move Right</em>.<p>
299     *
300     * @return true if buttons are typically ordered from left to right
301     * @since 1.0.3
302     *
303     * @see com.jgoodies.forms.builder.ButtonBarBuilder
304     * @see com.jgoodies.forms.factories.ButtonBarFactory
305     */
306    public abstract boolean isLeftToRightButtonOrder();
307
308}