org.eclipse.swt.graphics.Device Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH 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:
* Innoopract Informationssysteme GmbH - initial API and implementation
* EclipseSource - ongoing development
******************************************************************************/
package org.eclipse.swt.graphics;
import static org.eclipse.rap.rwt.internal.service.ContextProvider.getApplicationContext;
import org.eclipse.rap.rwt.internal.theme.CssFont;
import org.eclipse.rap.rwt.internal.theme.CssValue;
import org.eclipse.rap.rwt.internal.theme.SimpleSelector;
import org.eclipse.rap.rwt.internal.theme.ThemeUtil;
import org.eclipse.rap.rwt.internal.util.SerializableLock;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.internal.SerializableCompatibility;
import org.eclipse.swt.internal.graphics.ResourceFactory;
/**
* This class is the abstract superclass of all device objects,
* such as Display.
*
* This class is not intended to be directly used by clients.
*/
public abstract class Device implements Drawable, SerializableCompatibility {
// SWT code uses Device.class as the synchronization lock. This synchronize
// access from all over the application. In RWT we need a way to synchronize
// access from within a session. Therefore Device.class was replaced by the
// 'deviceLock'.
protected final SerializableLock deviceLock;
private boolean disposed;
public Device() {
deviceLock = new SerializableLock();
}
/**
* Returns the matching standard color for the given
* constant, which should be one of the color constants
* specified in class SWT. Any value other
* than one of the SWT color constants which is passed
* in will result in the color black. This color should
* not be free'd because it was allocated by the system,
* not the application.
*
* @param id the color constant
* @return the matching color
*
* @exception SWTException
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
* - ERROR_DEVICE_DISPOSED - if the receiver has been disposed
*
*
* @see SWT
*/
public Color getSystemColor( int id ) {
checkDevice();
ResourceFactory resourceFactory = getApplicationContext().getResourceFactory();
Color result;
switch( id ) {
case SWT.COLOR_TRANSPARENT:
result = resourceFactory.getColor( 0, 0, 0, 0 );
break;
case SWT.COLOR_WHITE:
result = resourceFactory.getColor( 255, 255, 255 );
break;
case SWT.COLOR_BLACK:
result = resourceFactory.getColor( 0, 0, 0 );
break;
case SWT.COLOR_RED:
result = resourceFactory.getColor( 255, 0, 0 );
break;
case SWT.COLOR_DARK_RED:
result = resourceFactory.getColor( 128, 0, 0 );
break;
case SWT.COLOR_GREEN:
result = resourceFactory.getColor( 0, 255, 0 );
break;
case SWT.COLOR_DARK_GREEN:
result = resourceFactory.getColor( 0, 128, 0 );
break;
case SWT.COLOR_YELLOW:
result = resourceFactory.getColor( 255, 255, 0 );
break;
case SWT.COLOR_DARK_YELLOW:
result = resourceFactory.getColor( 128, 128, 0 );
break;
case SWT.COLOR_BLUE:
result = resourceFactory.getColor( 0, 0, 255 );
break;
case SWT.COLOR_DARK_BLUE:
result = resourceFactory.getColor( 0, 0, 128 );
break;
case SWT.COLOR_MAGENTA:
result = resourceFactory.getColor( 255, 0, 255 );
break;
case SWT.COLOR_DARK_MAGENTA:
result = resourceFactory.getColor( 128, 0, 128 );
break;
case SWT.COLOR_CYAN:
result = resourceFactory.getColor( 0, 255, 255 );
break;
case SWT.COLOR_DARK_CYAN:
result = resourceFactory.getColor( 0, 128, 128 );
break;
case SWT.COLOR_GRAY:
result = resourceFactory.getColor( 192, 192, 192 );
break;
case SWT.COLOR_DARK_GRAY:
result = resourceFactory.getColor( 128, 128, 128 );
break;
default:
result = resourceFactory.getColor( 0, 0, 0 );
break;
}
return result;
}
/**
* Returns a reasonable font for applications to use.
* On some platforms, this will match the "default font"
* or "system font" if such can be found. This font
* should not be free'd because it was allocated by the
* system, not the application.
*
* Typically, applications which want the default look
* should simply not set the font on the widgets they
* create. Widgets are always created with the correct
* default font for the class of user-interface component
* they represent.
*
*
* @return a font
*
* @exception SWTException
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
* - ERROR_DEVICE_DISPOSED - if the receiver has been disposed
*
*/
public Font getSystemFont() {
checkDevice();
CssValue font = ThemeUtil.getCssValue( "Display", "font", SimpleSelector.DEFAULT );
return CssFont.createFont( ( CssFont )font );
}
/**
* Returns FontData objects which describe
* the fonts that match the given arguments. If the
* faceName is null, all fonts will be returned.
*
* @param faceName the name of the font to look for, or null
* @param scalable if true only scalable fonts are returned, otherwise only non-scalable fonts are returned.
* @return the matching font data
*
* @exception SWTException
* - ERROR_DEVICE_DISPOSED - if the receiver has been disposed
*
*
* @since 1.3
*/
public FontData[] getFontList( String faceName, boolean scalable ) {
checkDevice();
FontData[] result = new FontData[ 0 ];
if( scalable ) {
CssFont fontList
= ( CssFont )ThemeUtil.getCssValue( "Display", "rwt-fontlist", SimpleSelector.DEFAULT );
if( faceName == null ) {
result = new FontData[ fontList.family.length ];
for( int i = 0; i < result.length; i++ ) {
result[ i ] = new FontData( fontList.family[ i ], 0, SWT.NORMAL );
}
} else {
int counter = 0;
for( int i = 0; i < fontList.family.length; i++ ) {
if( fontList.family[ i ].startsWith( faceName ) ) {
counter++;
}
}
result = new FontData[ counter ];
counter = 0;
for( int i = 0; i < fontList.family.length; i++ ) {
if( fontList.family[ i ].startsWith( faceName ) ) {
result[ counter++ ] = new FontData( fontList.family[ i ], 0, SWT.NORMAL );
}
}
}
}
return result;
}
/**
* Returns a rectangle which describes the area of the receiver which is
* capable of displaying data.
*
* @return the client area
* @exception SWTException
* - ERROR_DEVICE_DISPOSED - if the receiver has been disposed
*
* @see #getBounds
* @since 1.2
*/
public Rectangle getClientArea() {
checkDevice();
return getBounds();
}
/**
* Returns the bit depth of the screen, which is the number of
* bits it takes to represent the number of unique colors that
* the screen is currently capable of displaying. This number
* will typically be one of 1, 8, 15, 16, 24 or 32.
*
* @return the depth of the screen
*
* @exception SWTException
* - ERROR_DEVICE_DISPOSED - if the receiver has been disposed
*
* @since 1.3
*/
public int getDepth() {
checkDevice();
return 16;
}
/**
* Returns a point whose x coordinate is the horizontal
* dots per inch of the display, and whose y coordinate
* is the vertical dots per inch of the display.
*
* @return the horizontal and vertical DPI
*
* @exception SWTException
* - ERROR_DEVICE_DISPOSED - if the receiver has been disposed
*
* @since 1.3
*/
public Point getDPI() {
checkDevice();
return new Point( 0, 0 );
}
/**
* Returns a rectangle describing the receiver's size and location.
*
* @return the bounding rectangle
* @exception SWTException
* - ERROR_DEVICE_DISPOSED - if the receiver has been disposed
*
* @since 1.2
*/
public Rectangle getBounds() {
checkDevice();
return new Rectangle( 0, 0, 0, 0 );
}
/**
* Disposes of the operating system resources associated with
* the receiver. After this method has been invoked, the receiver
* will answer true when sent the message
* isDisposed().
*
* @see #release
* @see #destroy
* @see #checkDevice
*/
public void dispose() {
synchronized( deviceLock ) {
if( !isDisposed() ) {
checkDevice();
release();
destroy();
disposed = true;
}
}
}
/**
* Returns true if the device has been disposed,
* and false otherwise.
*
* This method gets the dispose state for the device.
* When a device has been disposed, it is an error to
* invoke any other method using the device.
*
* @return true when the device is disposed and false otherwise
*/
public boolean isDisposed() {
synchronized( deviceLock ) {
return disposed;
}
}
/**
* Releases any internal resources .
*
* When a device is destroyed, resources that were acquired
* on behalf of the programmer need to be returned to the
* operating system. For example, if the device allocated a
* font to be used as the system font, this font would be
* freed in release. Also,to assist the garbage
* collector and minimize the amount of memory that is not
* reclaimed when the programmer keeps a reference to a
* disposed device, all fields except the handle are zero'd.
* The handle is needed by destroy.
*
* This method is called before destroy.
*
* If subclasses reimplement this method, they must
* call the super implementation.
*
*
* @see #dispose
* @see #destroy
*/
protected void release() {
}
/**
* Destroys the device . If the device does not have a handle,
* this method may do nothing depending on the device.
*
* This method is called after release.
*
* Subclasses are supposed to reimplement this method and not
* call the super implementation.
*
*
* @see #dispose
* @see #release
*/
protected void destroy() {
}
/**
* Throws an SWTException if the receiver can not
* be accessed by the caller. This may include both checks on
* the state of the receiver and more generally on the entire
* execution context. This method should be called by
* device implementors to enforce the standard SWT invariants.
*
* Currently, it is an error to invoke any method (other than
* isDisposed() and dispose()) on a
* device that has had its dispose() method called.
*
* In future releases of SWT, there may be more or fewer error
* checks and exceptions may be thrown for different reasons.
*
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
*
*/
protected void checkDevice() {
if( disposed ) {
SWT.error( SWT.ERROR_DEVICE_DISPOSED );
}
}
}
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