org.eclipse.swt.widgets.IME Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.swt.gtk.linux.ppc64le Show documentation
Standard Widget Toolkit for GTK on ppc64le
The newest version!
/*******************************************************************************
 * Copyright (c) 2007, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;


/**
 * Instances of this class represent input method editors.
 * These are typically in-line pre-edit text areas that allow
 * the user to compose characters from Far Eastern languages
 * such as Japanese, Chinese or Korean.
 *
 * 
 * Styles:
 * (none)
 * Events:
 * ImeComposition
 * 
 * 
 * IMPORTANT: This class is not intended to be subclassed.
 * 
 *
 * @see Sample code and further information
 *
 * @since 3.4
 * @noextend This class is not intended to be subclassed by clients.
 */
public class IME extends Widget {
	Canvas parent;
	int caretOffset;
	int startOffset;
	int commitCount;
	String text;
	int [] ranges;
	TextStyle [] styles;
	boolean inComposition;

/**
 * Prevents uninitialized instances from being created outside the package.
 */
IME () {
}

/**
 * Constructs a new instance of this class given its parent
 * and a style value describing its behavior and appearance.
 * 
 * The style value is either one of the style constants defined in
 * class SWT which is applicable to instances of this
 * class, or must be built by bitwise OR'ing together
 * (that is, using the int "|" operator) two or more
 * of those SWT style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * 
 *
 * @param parent a canvas control which will be the parent of the new instance (cannot be null)
 * @param style the style of control to construct
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the parent is null
 * 
 * @exception SWTException 
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
 *    ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
 * 
 *
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public IME (Canvas parent, int style) {
	super (parent, style);
	this.parent = parent;
	createWidget ();
}

void createWidget () {
	text = "";
	startOffset = -1;
	if (parent.getIME () == null) {
		parent.setIME (this);
	}
}

/**
 * Returns the offset of the caret from the start of the document.
 * -1 means that there is currently no active composition.
 * The caret is within the current composition.
 *
 * @return the caret offset
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getCaretOffset () {
	checkWidget ();
	return startOffset + caretOffset;
}

/**
 * Returns the commit count of the composition.  This is the
 * number of characters that have been composed.  When the
 * commit count is equal to the length of the composition
 * text, then the in-line edit operation is complete.
 *
 * @return the commit count
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see IME#getText
 */
public int getCommitCount () {
	checkWidget ();
	return commitCount;
}

/**
 * Returns the offset of the composition from the start of the document.
 * This is the start offset of the composition within the document and
 * in not changed by the input method editor itself during the in-line edit
 * session.
 *
 * @return the offset of the composition
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getCompositionOffset () {
	checkWidget ();
	return startOffset;
}

/**
 * Returns the ranges for the style that should be applied during the
 * in-line edit session.
 * 
 * The ranges array contains start and end pairs.  Each pair refers to
 * the corresponding style in the styles array.  For example, the pair
 * that starts at ranges[n] and ends at ranges[n+1] uses the style
 * at styles[n/2] returned by getStyles().
 * 
 * @return the ranges for the styles
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see IME#getStyles
 */
public int [] getRanges () {
	checkWidget ();
	if (ranges == null) return new int [0];
	int [] result = new int [ranges.length];
	for (int i = 0; i < result.length; i++) {
		result [i] = ranges [i] + startOffset;
	}
	return result;
}

/**
 * Returns the styles for the ranges.
 * 
 * The ranges array contains start and end pairs.  Each pair refers to
 * the corresponding style in the styles array.  For example, the pair
 * that starts at ranges[n] and ends at ranges[n+1] uses the style
 * at styles[n/2].
 * 
 *
 * @return the ranges for the styles
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see IME#getRanges
 */
public TextStyle [] getStyles () {
	checkWidget ();
	if (styles == null) return new TextStyle [0];
	TextStyle [] result = new TextStyle [styles.length];
	System.arraycopy (styles, 0, result, 0, styles.length);
	return result;
}

/**
 * Returns the composition text.
 * 
 * The text for an IME is the characters in the widget that
 * are in the current composition. When the commit count is
 * equal to the length of the composition text, then the
 * in-line edit operation is complete.
 * 
 *
 * @return the widget text
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public String getText () {
	checkWidget ();
	return text;
}

/**
 * Returns true if the caret should be wide, and
 * false otherwise.  In some languages, for example
 * Korean, the caret is typically widened to the width of the
 * current character in the in-line edit session.
 *
 * @return the wide caret state
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public boolean getWideCaret () {
	checkWidget ();
	return false;
}

@Override
long gtk_button_press_event (long widget, long event) {
	if (!isInlineEnabled ()) return 0;
	long imHandle = imHandle ();
	if (imHandle != 0) GTK.gtk_im_context_reset (imHandle);
	return 0;
}

@Override
long gtk_commit (long imcontext, long textPtr) {
	if (!isInlineEnabled ()) return 0;
	boolean doit = true;
	ranges = null;
	styles = null;
	caretOffset = commitCount = 0;
	if (textPtr != 0 && inComposition) {
		int length = C.strlen (textPtr);
		if (length != 0) {
			byte [] buffer = new byte [length];
			C.memmove (buffer, textPtr, length);
			char [] chars = Converter.mbcsToWcs (buffer);
			Event event = new Event();
			event.detail = SWT.COMPOSITION_CHANGED;
			event.start = startOffset;
			event.end = startOffset + text.length ();
			event.text = text = chars != null ? new String (chars) : "";
			commitCount = text.length();
			sendEvent (SWT.ImeComposition, event);
			doit = event.doit;
			text = "";
			startOffset = -1;
			commitCount = 0;
		}
	}
	inComposition = false;
	return doit ? 0 : 1;
}

@Override
long gtk_preedit_changed (long imcontext) {
	if (!isInlineEnabled ()) return 0;
	ranges = null;
	styles = null;
	commitCount = 0;
	long imHandle = imHandle ();
	long [] preeditString = new long [1];
	long [] pangoAttrs = new long [1];
	int [] cursorPos = new int [1];
	GTK.gtk_im_context_get_preedit_string (imHandle, preeditString, pangoAttrs, cursorPos);
	caretOffset = cursorPos [0];
	char [] chars = null;
	if (preeditString [0] != 0) {
		int length = C.strlen (preeditString [0]);
		byte [] buffer = new byte [length];
		C.memmove (buffer, preeditString [0], length);
		chars = Converter.mbcsToWcs (buffer);

		/*
		 * Bug 571740: GTK has a bug in 'gtk-im-context-simple' IM context
		 * which is default. It incorrectly reports 'cursorPos' in bytes
		 * instead of characters. Somewhere around GTK 3.24.26 this IM
		 * was reworked and it started sending 'gtk_preedit_changed' where
		 * it previously did not, causing SWT to step on that old bug.
		 * If caret's position is already at the end, this will result in
		 * trying to set caret outside the text. The workaround is to limit
		 * caret's position.
		 */
		caretOffset = Math.min(caretOffset, chars.length);

		if (pangoAttrs [0] != 0) {
			int count = 0;
			long iterator = OS.pango_attr_list_get_iterator (pangoAttrs [0]);
			while (OS.pango_attr_iterator_next (iterator)) count++;
			OS.pango_attr_iterator_destroy (iterator);
			ranges = new int [count * 2];
			styles = new TextStyle [count];
			iterator = OS.pango_attr_list_get_iterator (pangoAttrs [0]);
			PangoAttrColor attrColor = new PangoAttrColor ();
			PangoAttrInt attrInt = new PangoAttrInt ();
			int [] start = new int [1];
			int [] end = new int [1];
			for (int i = 0; i < count; i++) {
				OS.pango_attr_iterator_range (iterator, start, end);
				ranges [i * 2] = (int)OS.g_utf16_pointer_to_offset (preeditString [0], preeditString [0] + start [0]);
				ranges [i * 2 + 1] = (int)OS.g_utf16_pointer_to_offset (preeditString [0], preeditString [0] + end [0]) - 1;
				styles [i] = new TextStyle (null, null, null);
				long attr = OS.pango_attr_iterator_get (iterator, OS.PANGO_ATTR_FOREGROUND);
				if (attr != 0) {
					OS.memmove (attrColor, attr, PangoAttrColor.sizeof);
					GdkRGBA rgba = new GdkRGBA ();
					rgba.alpha = 1.0;
					// Manual conversion since PangoAttrColor is a special case.
					// It uses GdkColor style colors but is supported on GTK3.
					rgba.red = (attrColor.color_red & 0xFFFF) / (float)0xFFFF;
					rgba.green = (attrColor.color_green & 0xFFFF) / (float)0xFFFF;
					rgba.blue = (attrColor.color_blue & 0xFFFF) / (float)0xFFFF;
					styles [i].foreground = Color.gtk_new(display, rgba);
				}
				attr = OS.pango_attr_iterator_get (iterator, OS.PANGO_ATTR_BACKGROUND);
				if (attr != 0) {
					OS.memmove (attrColor, attr, PangoAttrColor.sizeof);
					GdkRGBA rgba = new GdkRGBA ();
					rgba.alpha = 1.0;
					// Manual conversion since PangoAttrColor is a special case.
					// It uses GdkColor style colors but is supported on GTK3.
					rgba.red = (attrColor.color_red & 0xFFFF) / (float)0xFFFF;
					rgba.green = (attrColor.color_green & 0xFFFF) / (float)0xFFFF;
					rgba.blue = (attrColor.color_blue & 0xFFFF) / (float)0xFFFF;
					styles [i].background = Color.gtk_new(display, rgba);
				}
				attr = OS.pango_attr_iterator_get (iterator, OS.PANGO_ATTR_UNDERLINE);
				if (attr != 0) {
					OS.memmove (attrInt, attr, PangoAttrInt.sizeof);
					styles [i].underline = attrInt.value != OS.PANGO_UNDERLINE_NONE;
					styles [i].underlineStyle = SWT.UNDERLINE_SINGLE;
					switch (attrInt.value) {
						case OS.PANGO_UNDERLINE_DOUBLE:
							styles [i].underlineStyle = SWT.UNDERLINE_DOUBLE;
							break;
						case OS.PANGO_UNDERLINE_ERROR:
							styles [i].underlineStyle = SWT.UNDERLINE_ERROR;
							break;
					}
					if (styles [i].underline) {
						attr = OS.pango_attr_iterator_get(iterator, OS.PANGO_ATTR_UNDERLINE_COLOR);
						if (attr != 0) {
							GdkRGBA rgba = new GdkRGBA ();
							rgba.alpha = 1.0;
							// Manual conversion since PangoAttrColor is a special case.
							// It uses GdkColor style colors but is supported on GTK3.
							rgba.red = (attrColor.color_red & 0xFFFF) / (float)0xFFFF;
							rgba.green = (attrColor.color_green & 0xFFFF) / (float)0xFFFF;
							rgba.blue = (attrColor.color_blue & 0xFFFF) / (float)0xFFFF;
							styles [i].underlineColor = Color.gtk_new(display, rgba);
						}
					}
				}
				OS.pango_attr_iterator_next (iterator);
			}
			OS.pango_attr_iterator_destroy (iterator);
			OS.pango_attr_list_unref (pangoAttrs [0]);
		}
		OS.g_free (preeditString [0]);
	}
	if (chars != null) {
		if (text.length() == 0) {
			/*
			* Bug in GTK. In Solaris, the IME sends multiple
			* preedit_changed signals with an empty text.
			* This behavior is not correct for SWT and can
			* cause the editor to replace its current selection
			* with an empty string. The fix is to ignore any
			* preedit_changed signals with an empty text when
			* the preedit buffer is already empty.
			*/
			if (chars.length == 0) return 0;
			startOffset = -1;
		}
		int end = startOffset + text.length();
		if (startOffset == -1) {
			Event event = new Event ();
			event.detail = SWT.COMPOSITION_SELECTION;
			sendEvent (SWT.ImeComposition, event);
			startOffset = event.start;
			end = event.end;
		}
		inComposition = true;
		Event event = new Event ();
		event.detail = SWT.COMPOSITION_CHANGED;
		event.start = startOffset;
		event.end = end;
		event.text = text = chars != null ? new String (chars) : "";
		sendEvent (SWT.ImeComposition, event);
	}
	return 1;
}

long imHandle () {
	return parent.imHandle ();
}

boolean isInlineEnabled () {
	return hooks (SWT.ImeComposition);
}

@Override
void releaseParent () {
	super.releaseParent ();
	if (this == parent.getIME ()) parent.setIME (null);
}

@Override
void releaseWidget () {
	super.releaseWidget ();
	parent = null;
	text = null;
	styles = null;
	ranges = null;
}

/**
 * Sets the offset of the composition from the start of the document.
 * This is the start offset of the composition within the document and
 * in not changed by the input method editor itself during the in-line edit
 * session but may need to be changed by clients of the IME.  For example,
 * if during an in-line edit operation, a text editor inserts characters
 * above the IME, then the IME must be informed that the composition
 * offset has changed.
 *
 * @param offset the offset of the composition
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setCompositionOffset (int offset) {
	checkWidget ();
	if (offset < 0) return;
	if (startOffset != -1) {
		startOffset = offset;
	}
}

}