/*******************************************************************************
 * Copyright (c) 2003, 2018 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.browser;

import java.util.*;
import java.util.List;

import org.eclipse.swt.*;
import org.eclipse.swt.widgets.*;

abstract class WebBrowser {
	Browser browser;
	Map<Integer, BrowserFunction> functions = new HashMap<> ();
	AuthenticationListener[] authenticationListeners = new AuthenticationListener[0];
	CloseWindowListener[] closeWindowListeners = new CloseWindowListener[0];
	LocationListener[] locationListeners = new LocationListener[0];
	OpenWindowListener[] openWindowListeners = new OpenWindowListener[0];
	ProgressListener[] progressListeners = new ProgressListener[0];
	StatusTextListener[] statusTextListeners = new StatusTextListener[0];
	TitleListener[] titleListeners = new TitleListener[0];
	VisibilityWindowListener[] visibilityWindowListeners = new VisibilityWindowListener[0];
	boolean jsEnabledOnNextPage = true, jsEnabled = true;
	int nextFunctionIndex = 1;
	Object evaluateResult;

	static final String ERROR_ID = "org.eclipse.swt.browser.error"; // $NON-NLS-1$
	static final String EXECUTE_ID = "SWTExecuteTemporaryFunction"; // $NON-NLS-1$

	static List<String[]> NativePendingCookies = new ArrayList<> ();
	static String CookieName, CookieValue, CookieUrl;
	static boolean CookieResult;
	static Runnable NativeClearSessions;
	static Runnable NativeGetCookie;
	static Runnable NativeSetCookie;

	/* Key Mappings */
	static final int [][] KeyTable = {
		/* Keyboard and Mouse Masks */
		{18,	SWT.ALT},
		{16,	SWT.SHIFT},
		{17,	SWT.CONTROL},
		{224,	SWT.COMMAND},

		/* Literal Keys */
		{65,	'a'},
		{66,	'b'},
		{67,	'c'},
		{68,	'd'},
		{69,	'e'},
		{70,	'f'},
		{71,	'g'},
		{72,	'h'},
		{73,	'i'},
		{74,	'j'},
		{75,	'k'},
		{76,	'l'},
		{77,	'm'},
		{78,	'n'},
		{79,	'o'},
		{80,	'p'},
		{81,	'q'},
		{82,	'r'},
		{83,	's'},
		{84,	't'},
		{85,	'u'},
		{86,	'v'},
		{87,	'w'},
		{88,	'x'},
		{89,	'y'},
		{90,	'z'},
		{48,	'0'},
		{49,	'1'},
		{50,	'2'},
		{51,	'3'},
		{52,	'4'},
		{53,	'5'},
		{54,	'6'},
		{55,	'7'},
		{56,	'8'},
		{57,	'9'},
		{32,	' '},
		{59,	';'},
		{61,	'='},
		{188,	','},
		{190,	'.'},
		{191,	'/'},
		{219,	'['},
		{221,	']'},
		{222,	'\''},
		{192,	'`'},
		{220,	'\\'},
		{108,	'|'},
		{226,	'<'},

		/* Non-Numeric Keypad Keys */
		{37,	SWT.ARROW_LEFT},
		{39,	SWT.ARROW_RIGHT},
		{38,	SWT.ARROW_UP},
		{40,	SWT.ARROW_DOWN},
		{45,	SWT.INSERT},
		{36,	SWT.HOME},
		{35,	SWT.END},
		{46,	SWT.DEL},
		{33,	SWT.PAGE_UP},
		{34,	SWT.PAGE_DOWN},

		/* Virtual and Ascii Keys */
		{8,		SWT.BS},
		{13,	SWT.CR},
		{9,		SWT.TAB},
		{27,	SWT.ESC},
		{12,	SWT.DEL},

		/* Functions Keys */
		{112,	SWT.F1},
		{113,	SWT.F2},
		{114,	SWT.F3},
		{115,	SWT.F4},
		{116,	SWT.F5},
		{117,	SWT.F6},
		{118,	SWT.F7},
		{119,	SWT.F8},
		{120,	SWT.F9},
		{121,	SWT.F10},
		{122,	SWT.F11},
		{123,	SWT.F12},
		{124,	SWT.F13},
		{125,	SWT.F14},
		{126,	SWT.F15},
		{127,	0},
		{128,	0},
		{129,	0},
		{130,	0},
		{131,	0},
		{132,	0},
		{133,	0},
		{134,	0},
		{135,	0},

		/* Numeric Keypad Keys */
		{96,	SWT.KEYPAD_0},
		{97,	SWT.KEYPAD_1},
		{98,	SWT.KEYPAD_2},
		{99,	SWT.KEYPAD_3},
		{100,	SWT.KEYPAD_4},
		{101,	SWT.KEYPAD_5},
		{102,	SWT.KEYPAD_6},
		{103,	SWT.KEYPAD_7},
		{104,	SWT.KEYPAD_8},
		{105,	SWT.KEYPAD_9},
		{14,	SWT.KEYPAD_CR},
		{107,	SWT.KEYPAD_ADD},
		{109,	SWT.KEYPAD_SUBTRACT},
		{106,	SWT.KEYPAD_MULTIPLY},
		{111,	SWT.KEYPAD_DIVIDE},
		{110,	SWT.KEYPAD_DECIMAL},

		/* Other keys */
		{20,	SWT.CAPS_LOCK},
		{144,	SWT.NUM_LOCK},
		{145,	SWT.SCROLL_LOCK},
		{44,	SWT.PRINT_SCREEN},
		{6,		SWT.HELP},
		{19,	SWT.PAUSE},
		{3,		SWT.BREAK},

		/* WebKit-specific */
		{186,	';'},
		{187,	'='},
		{189,	'-'},
	};

public class EvaluateFunction extends BrowserFunction {
	public EvaluateFunction (Browser browser, String name) {
		super (browser, name, true, new String[0], false);
	}
	@Override
	public Object function (Object[] arguments) {
		if (arguments[0] instanceof String string) {
			if (string.startsWith (ERROR_ID)) {
				String errorString = ExtractError (string);
				if (errorString.length () > 0) {
					evaluateResult = new SWTException (SWT.ERROR_FAILED_EVALUATE, errorString);
				} else {
					evaluateResult = new SWTException (SWT.ERROR_FAILED_EVALUATE);
				}
				return null;
			}
		}
		evaluateResult = arguments[0];
		return null;
	}
}

public void addAuthenticationListener (AuthenticationListener listener) {
	AuthenticationListener[] newAuthenticationListeners = new AuthenticationListener[authenticationListeners.length + 1];
	System.arraycopy(authenticationListeners, 0, newAuthenticationListeners, 0, authenticationListeners.length);
	authenticationListeners = newAuthenticationListeners;
	authenticationListeners[authenticationListeners.length - 1] = listener;
}

public void addCloseWindowListener (CloseWindowListener listener) {
	CloseWindowListener[] newCloseWindowListeners = new CloseWindowListener[closeWindowListeners.length + 1];
	System.arraycopy(closeWindowListeners, 0, newCloseWindowListeners, 0, closeWindowListeners.length);
	closeWindowListeners = newCloseWindowListeners;
	closeWindowListeners[closeWindowListeners.length - 1] = listener;
}

public void addLocationListener (LocationListener listener) {
	LocationListener[] newLocationListeners = new LocationListener[locationListeners.length + 1];
	System.arraycopy(locationListeners, 0, newLocationListeners, 0, locationListeners.length);
	locationListeners = newLocationListeners;
	locationListeners[locationListeners.length - 1] = listener;
}

public void addOpenWindowListener (OpenWindowListener listener) {
	OpenWindowListener[] newOpenWindowListeners = new OpenWindowListener[openWindowListeners.length + 1];
	System.arraycopy(openWindowListeners, 0, newOpenWindowListeners, 0, openWindowListeners.length);
	openWindowListeners = newOpenWindowListeners;
	openWindowListeners[openWindowListeners.length - 1] = listener;
}

public void addProgressListener (ProgressListener listener) {
	ProgressListener[] newProgressListeners = new ProgressListener[progressListeners.length + 1];
	System.arraycopy(progressListeners, 0, newProgressListeners, 0, progressListeners.length);
	progressListeners = newProgressListeners;
	progressListeners[progressListeners.length - 1] = listener;
}

public void addStatusTextListener (StatusTextListener listener) {
	StatusTextListener[] newStatusTextListeners = new StatusTextListener[statusTextListeners.length + 1];
	System.arraycopy(statusTextListeners, 0, newStatusTextListeners, 0, statusTextListeners.length);
	statusTextListeners = newStatusTextListeners;
	statusTextListeners[statusTextListeners.length - 1] = listener;
}

public void addTitleListener (TitleListener listener) {
	TitleListener[] newTitleListeners = new TitleListener[titleListeners.length + 1];
	System.arraycopy(titleListeners, 0, newTitleListeners, 0, titleListeners.length);
	titleListeners = newTitleListeners;
	titleListeners[titleListeners.length - 1] = listener;
}

public void addVisibilityWindowListener (VisibilityWindowListener listener) {
	VisibilityWindowListener[] newVisibilityWindowListeners = new VisibilityWindowListener[visibilityWindowListeners.length + 1];
	System.arraycopy(visibilityWindowListeners, 0, newVisibilityWindowListeners, 0, visibilityWindowListeners.length);
	visibilityWindowListeners = newVisibilityWindowListeners;
	visibilityWindowListeners[visibilityWindowListeners.length - 1] = listener;
}

public abstract boolean back ();

public static void clearSessions () {
	if (NativeClearSessions != null) NativeClearSessions.run ();
}

public static String GetCookie (String name, String url) {
	CookieName = name; CookieUrl = url; CookieValue = null;
	if (NativeGetCookie != null) NativeGetCookie.run ();
	String result = CookieValue;
	CookieName = CookieValue = CookieUrl = null;
	return result;
}

public static boolean SetCookie (String value, String url, boolean addToPending) {
	CookieValue = value; CookieUrl = url;
	CookieResult = false;
	if (NativeSetCookie != null) {
		NativeSetCookie.run ();
	} else {
		if (addToPending && NativePendingCookies != null) {
			NativePendingCookies.add (new String[] {value, url});
		}
	}
	CookieValue = CookieUrl = null;
	return CookieResult;
}

static void SetPendingCookies (List<String[]> pendingCookies) {
	for (String[] current : pendingCookies) {
		SetCookie (current[0], current[1], false);
	}
}

public abstract void create (Composite parent, int style);

static String CreateErrorString (String error) {
	return ERROR_ID + error;
}

static String ExtractError (String error) {
	return error.substring (ERROR_ID.length ());
}

public boolean close () {
	return true;
}

public void createFunction (BrowserFunction function) {
	/*
	 * If an existing function with the same name is found then
	 * remove it so that it is not recreated on subsequent pages
	 * (the new function overwrites the old one).
	 */
	for (BrowserFunction current : functions.values()) {
		if (current.name.equals (function.name)) {
			deregisterFunction (current);
			break;
		}
	}

	function.index = getNextFunctionIndex ();
	registerFunction (function);

	StringBuilder functionBuffer = new StringBuilder (function.name);
	functionBuffer.append (" = function "); //$NON-NLS-1$
	functionBuffer.append (function.name);
	functionBuffer.append ("() {var result = callJava("); //$NON-NLS-1$
	functionBuffer.append (function.index);
	functionBuffer.append (",'"); //$NON-NLS-1$
	functionBuffer.append (function.token);
	functionBuffer.append ("',Array.prototype.slice.call(arguments)); if (typeof result == 'string' && result.indexOf('"); //$NON-NLS-1$
	functionBuffer.append (ERROR_ID);
	functionBuffer.append ("') == 0) {var error = new Error(result.substring("); //$NON-NLS-1$
	functionBuffer.append (ERROR_ID.length ());
	functionBuffer.append (")); throw error;} return result;};"); //$NON-NLS-1$

	String javaCallDeclaration = getJavaCallDeclaration();

	StringBuilder buffer = new StringBuilder ();
	buffer.append (javaCallDeclaration);
	if (function.top) {
		buffer.append (functionBuffer.toString ());
	}

	buffer.append ("var frameIds = null;"); //$NON-NLS-1$
	if (function.frameNames != null) {
		buffer.append ("frameIds = {"); //$NON-NLS-1$
		for (String frameName : function.frameNames) {
			buffer.append ('\'');
			buffer.append (frameName);
			buffer.append ("':1,"); //$NON-NLS-1$
		}
		if (function.frameNames.length > 0) {
			buffer.deleteCharAt(buffer.length () - 1);
		}
		buffer.append ("};"); //$NON-NLS-1$
	}

	buffer.append ("for (var i = 0; i < frames.length; i++) {try {if (!frameIds || (frames[i].name && frameIds[frames[i].name])) {"); //$NON-NLS-1$
	buffer.append ("if (!frames[i].callJava) {frames[i].callJava = window.callJava;} frames[i]."); //$NON-NLS-1$
	buffer.append (functionBuffer.toString ());
	buffer.append ("}} catch(e) {}};"); //$NON-NLS-1$

	function.functionString = buffer.toString ();
	nonBlockingExecute (function.functionString);
}

/**
 * Designed to be overridden.
 * @return javaScript code that defines the 'callJava' syntax for javascript.
 */
String getJavaCallDeclaration() {
	return    "if (!window.callJava) {\n"
			+ "		window.callJava = function callJava(index, token, args) {\n"
			+ "			return external.callJava(index,token,args);\n"
			+ "		}\n"
			+ "};\n";
}

void deregisterFunction (BrowserFunction function) {
	functions.remove (function.index);
}

public void destroyFunction (BrowserFunction function) {
	String deleteString = getDeleteFunctionString (function.name);
	StringBuilder buffer = new StringBuilder ("for (var i = 0; i < frames.length; i++) {try {frames[i].eval(\""); //$NON-NLS-1$
	buffer.append (deleteString);
	buffer.append ("\");} catch (e) {}}"); //$NON-NLS-1$
	nonBlockingExecute (buffer.toString ());
	nonBlockingExecute (deleteString);
	deregisterFunction (function);
}

// Designed to be overridden by platform implementations, used for optimization and avoiding deadlocks.
// Webkit2 is async, we often don't need to bother waiting for a return type if we never use it.
void nonBlockingExecute(String script) {
	execute(script);
}

public abstract boolean execute (String script);

public Object evaluate (String script, boolean trusted) throws SWTException {
	return evaluate(script);
}

public Object evaluate (String script) throws SWTException {
	// Gtk Developer note:
	// Webkit1 uses this mechanism.
	// Webkit2 uses a different mechanism. See WebKit:evaluate();
	BrowserFunction function = new EvaluateFunction (browser, ""); // $NON-NLS-1$
	int index = getNextFunctionIndex ();
	function.index = index;
	function.isEvaluate = true;  // Note, Webkit2 doesn't use 'isEvaluate' machinery because it doesn't use a function for evaluation.
	registerFunction (function);
	String functionName = EXECUTE_ID + index;

	StringBuilder buffer = new StringBuilder ("window."); // $NON-NLS-1$
	buffer.append (functionName);
	buffer.append (" = function "); // $NON-NLS-1$
	buffer.append (functionName);
	buffer.append ("() {\n"); // $NON-NLS-1$
	buffer.append (script);
	buffer.append ("\n};"); // $NON-NLS-1$
	nonBlockingExecute (buffer.toString ());

	buffer = new StringBuilder ("if (window."); // $NON-NLS-1$
	buffer.append (functionName);
	buffer.append (" == undefined) {window.external.callJava("); // $NON-NLS-1$
	buffer.append (index);
	buffer.append (",'"); //$NON-NLS-1$
	buffer.append (function.token);
	buffer.append ("', ['"); // $NON-NLS-1$
	buffer.append (ERROR_ID);
	buffer.append ("']);} else {try {var result = "); // $NON-NLS-1$
	buffer.append (functionName);
	buffer.append ("(); window.external.callJava("); // $NON-NLS-1$
	buffer.append (index);
	buffer.append (",'"); //$NON-NLS-1$
	buffer.append (function.token);
	buffer.append ("', [result]);} catch (e) {window.external.callJava("); // $NON-NLS-1$
	buffer.append (index);
	buffer.append (",'"); //$NON-NLS-1$
	buffer.append (function.token);
	buffer.append ("', ['"); // $NON-NLS-1$
	buffer.append (ERROR_ID);
	buffer.append ("' + e.message]);}}"); // $NON-NLS-1$
	nonBlockingExecute (buffer.toString ());
	nonBlockingExecute (getDeleteFunctionString (functionName));
	deregisterFunction (function);

	Object result = evaluateResult;
	evaluateResult = null;
	if (result instanceof SWTException) throw (SWTException)result;
	return result;
}

public abstract boolean forward ();

public abstract String getBrowserType ();

String getDeleteFunctionString (String functionName) {
	return "delete window." + functionName;	//$NON-NLS-1$
}

int getNextFunctionIndex () {
	return nextFunctionIndex++;
}

public abstract String getText ();

public abstract String getUrl ();

public Object getWebBrowser () {
	return null;
}

public abstract boolean isBackEnabled ();

public boolean isFocusControl () {
	return false;
}

public abstract boolean isForwardEnabled ();

public abstract void refresh ();

void registerFunction (BrowserFunction function) {
	functions.put (function.index, function);
}

public void removeAuthenticationListener (AuthenticationListener listener) {
	if (authenticationListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < authenticationListeners.length; i++) {
		if (listener == authenticationListeners[i]) {
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (authenticationListeners.length == 1) {
		authenticationListeners = new AuthenticationListener[0];
		return;
	}
	AuthenticationListener[] newAuthenticationListeners = new AuthenticationListener[authenticationListeners.length - 1];
	System.arraycopy (authenticationListeners, 0, newAuthenticationListeners, 0, index);
	System.arraycopy (authenticationListeners, index + 1, newAuthenticationListeners, index, authenticationListeners.length - index - 1);
	authenticationListeners = newAuthenticationListeners;
}

public void removeCloseWindowListener (CloseWindowListener listener) {
	if (closeWindowListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < closeWindowListeners.length; i++) {
		if (listener == closeWindowListeners[i]){
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (closeWindowListeners.length == 1) {
		closeWindowListeners = new CloseWindowListener[0];
		return;
	}
	CloseWindowListener[] newCloseWindowListeners = new CloseWindowListener[closeWindowListeners.length - 1];
	System.arraycopy (closeWindowListeners, 0, newCloseWindowListeners, 0, index);
	System.arraycopy (closeWindowListeners, index + 1, newCloseWindowListeners, index, closeWindowListeners.length - index - 1);
	closeWindowListeners = newCloseWindowListeners;
}

public void removeLocationListener (LocationListener listener) {
	if (locationListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < locationListeners.length; i++) {
		if (listener == locationListeners[i]){
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (locationListeners.length == 1) {
		locationListeners = new LocationListener[0];
		return;
	}
	LocationListener[] newLocationListeners = new LocationListener[locationListeners.length - 1];
	System.arraycopy (locationListeners, 0, newLocationListeners, 0, index);
	System.arraycopy (locationListeners, index + 1, newLocationListeners, index, locationListeners.length - index - 1);
	locationListeners = newLocationListeners;
}

public void removeOpenWindowListener (OpenWindowListener listener) {
	if (openWindowListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < openWindowListeners.length; i++) {
		if (listener == openWindowListeners[i]){
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (openWindowListeners.length == 1) {
		openWindowListeners = new OpenWindowListener[0];
		return;
	}
	OpenWindowListener[] newOpenWindowListeners = new OpenWindowListener[openWindowListeners.length - 1];
	System.arraycopy (openWindowListeners, 0, newOpenWindowListeners, 0, index);
	System.arraycopy (openWindowListeners, index + 1, newOpenWindowListeners, index, openWindowListeners.length - index - 1);
	openWindowListeners = newOpenWindowListeners;
}

public void removeProgressListener (ProgressListener listener) {
	if (progressListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < progressListeners.length; i++) {
		if (listener == progressListeners[i]){
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (progressListeners.length == 1) {
		progressListeners = new ProgressListener[0];
		return;
	}
	ProgressListener[] newProgressListeners = new ProgressListener[progressListeners.length - 1];
	System.arraycopy (progressListeners, 0, newProgressListeners, 0, index);
	System.arraycopy (progressListeners, index + 1, newProgressListeners, index, progressListeners.length - index - 1);
	progressListeners = newProgressListeners;
}

public void removeStatusTextListener (StatusTextListener listener) {
	if (statusTextListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < statusTextListeners.length; i++) {
		if (listener == statusTextListeners[i]){
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (statusTextListeners.length == 1) {
		statusTextListeners = new StatusTextListener[0];
		return;
	}
	StatusTextListener[] newStatusTextListeners = new StatusTextListener[statusTextListeners.length - 1];
	System.arraycopy (statusTextListeners, 0, newStatusTextListeners, 0, index);
	System.arraycopy (statusTextListeners, index + 1, newStatusTextListeners, index, statusTextListeners.length - index - 1);
	statusTextListeners = newStatusTextListeners;
}

public void removeTitleListener (TitleListener listener) {
	if (titleListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < titleListeners.length; i++) {
		if (listener == titleListeners[i]){
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (titleListeners.length == 1) {
		titleListeners = new TitleListener[0];
		return;
	}
	TitleListener[] newTitleListeners = new TitleListener[titleListeners.length - 1];
	System.arraycopy (titleListeners, 0, newTitleListeners, 0, index);
	System.arraycopy (titleListeners, index + 1, newTitleListeners, index, titleListeners.length - index - 1);
	titleListeners = newTitleListeners;
}

public void removeVisibilityWindowListener (VisibilityWindowListener listener) {
	if (visibilityWindowListeners.length == 0) return;
	int index = -1;
	for (int i = 0; i < visibilityWindowListeners.length; i++) {
		if (listener == visibilityWindowListeners[i]){
			index = i;
			break;
		}
	}
	if (index == -1) return;
	if (visibilityWindowListeners.length == 1) {
		visibilityWindowListeners = new VisibilityWindowListener[0];
		return;
	}
	VisibilityWindowListener[] newVisibilityWindowListeners = new VisibilityWindowListener[visibilityWindowListeners.length - 1];
	System.arraycopy (visibilityWindowListeners, 0, newVisibilityWindowListeners, 0, index);
	System.arraycopy (visibilityWindowListeners, index + 1, newVisibilityWindowListeners, index, visibilityWindowListeners.length - index - 1);
	visibilityWindowListeners = newVisibilityWindowListeners;
}

boolean sendKeyEvent (Event event) {
	int traversal = SWT.TRAVERSE_NONE;
	boolean traverseDoit = true;
	switch (event.keyCode) {
		case SWT.ESC: {
			traversal = SWT.TRAVERSE_ESCAPE;
			traverseDoit = true;
			break;
		}
		case SWT.CR: {
			traversal = SWT.TRAVERSE_RETURN;
			traverseDoit = false;
			break;
		}
		case SWT.ARROW_DOWN:
		case SWT.ARROW_RIGHT: {
			traversal = SWT.TRAVERSE_ARROW_NEXT;
			traverseDoit = false;
			break;
		}
		case SWT.ARROW_UP:
		case SWT.ARROW_LEFT: {
			traversal = SWT.TRAVERSE_ARROW_PREVIOUS;
			traverseDoit = false;
			break;
		}
		case SWT.TAB: {
			traversal = (event.stateMask & SWT.SHIFT) != 0 ? SWT.TRAVERSE_TAB_PREVIOUS : SWT.TRAVERSE_TAB_NEXT;
			traverseDoit = (event.stateMask & SWT.CTRL) != 0;
			break;
		}
		case SWT.PAGE_DOWN: {
			if ((event.stateMask & SWT.CTRL) != 0) {
				traversal = SWT.TRAVERSE_PAGE_NEXT;
				traverseDoit = true;
			}
			break;
		}
		case SWT.PAGE_UP: {
			if ((event.stateMask & SWT.CTRL) != 0) {
				traversal = SWT.TRAVERSE_PAGE_PREVIOUS;
				traverseDoit = true;
			}
			break;
		}
		default: {
			if (translateMnemonics ()) {
				if (event.character != 0 && (event.stateMask & (SWT.ALT | SWT.CTRL)) == SWT.ALT) {
					traversal = SWT.TRAVERSE_MNEMONIC;
					traverseDoit = true;
				}
			}
			break;
		}
	}

	boolean doit = true;
	if (traversal != SWT.TRAVERSE_NONE) {
		boolean oldEventDoit = event.doit;
		event.doit = traverseDoit;
		doit = !browser.traverse (traversal, event);
		event.doit = oldEventDoit;
	}
	if (doit) {
		browser.notifyListeners (event.type, event);
		doit = event.doit;
	}
	return doit;
}

public void setBrowser (Browser browser) {
	this.browser = browser;
}

public abstract boolean setText (String html, boolean trusted);

public abstract boolean setUrl (String url, String postData, String[] headers);

public abstract void stop ();

int translateKey (int key) {
	for (int[] element : KeyTable) {
		if (element[0] == key) return element[1];
	}
	return 0;
}

boolean translateMnemonics () {
	return true;
}

}
