/*

     File: Browser.m 

 Abstract: Browser JavaScript class.  This

 file contains only one function that returns a reference to the JavaScript

 class definition for the browser object.  The browser object allows

 JavaScripts running in either the WebView's JavaScript context or in

 the Controller's JavaScript context to access the main browser

 window and items it contains.  This class also allows scripts

 running in either context to run JavaScripts in the main WebView's

 JavaScript JavaScript Context. 

  Version: 1.1 

 Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple 

 Inc. ("Apple") in consideration of your agreement to the following 

 terms, and your use, installation, modification or redistribution of 

 this Apple software constitutes acceptance of these terms.  If you do 

 not agree with these terms, please do not use, install, modify or 

 redistribute this Apple software. 

 In consideration of your agreement to abide by the following terms, and 

 subject to these terms, Apple grants you a personal, non-exclusive 

 license, under Apple's copyrights in this original Apple software (the 

 "Apple Software"), to use, reproduce, modify and redistribute the Apple 

 Software, with or without modifications, in source and/or binary forms; 

 provided that if you redistribute the Apple Software in its entirety and 

 without modifications, you must retain this notice and the following 

 text and disclaimers in all such redistributions of the Apple Software. 

 Neither the name, trademarks, service marks or logos of Apple Inc. may 

 be used to endorse or promote products derived from the Apple Software 

 without specific prior written permission from Apple.  Except as 

 expressly stated in this notice, no other rights or licenses, express or 

 implied, are granted by Apple herein, including but not limited to any 

 patent rights that may be infringed by your derivative works or by other 

 works in which the Apple Software may be incorporated. 

 The Apple Software is provided by Apple on an "AS IS" basis.  APPLE 

 MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION 

 THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS 

 FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND 

 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS. 

 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL 

 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 

 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 

 INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, 

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 AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE), 

 STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE 

 POSSIBILITY OF SUCH DAMAGE. 

 Copyright (C) 2011 Apple Inc. All Rights Reserved. 

 */

#import <Cocoa/Cocoa.h>

#import "Browser.h"

#import "Controller.h"

#import "NSStringExtras.h"

    /* getter callback for the 'progress' property */

static JSValueRef browserProgress( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

        /* return true if the progress bar is visible */

    return JSValueMakeBoolean( ctx, ( [cself.progressBar isHidden] ? false : true ) );

}

    /* setter callback for the 'progress' property */

static bool browserSetProgress( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef value, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

    bool theResult = false;

        /* verify that the value is of the proper type */

    if ( JSValueIsBoolean( ctx, value ) ) {

            /* start/stop the progress bar - the progress

            bar has been set to hide itself when it is not

            animating.  */

        if ( JSValueToBoolean( ctx, value ) ) {

            [cself.progressBar startAnimation: cself];

        } else {

            [cself.progressBar stopAnimation: cself];

        }

            /* return success */

        theResult = true;

    }

    return theResult;

}

    /* getter callback for the 'loading' property */

static JSValueRef browserLoading( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

        /* return true if we are in the midst of loading a page */

    return JSValueMakeBoolean( ctx, ( cself.isLoadingPage ? true : false ) );

}

    /* getter callback for the 'message' property */

static JSValueRef browserMessage( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

        /* return the text currently displayed at the bottom of the window */

    return JSValueMakeString( ctx, [[cself.messageText stringValue] jsStringValue] );

}

    /* setter callback for the 'message' property */

static bool browserSetMessage( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef value, JSValueRef* exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

    bool theResult = false;

        /* verify that the new value is of the proper type */

    if ( JSValueIsString( ctx, value ) ) {

            /* display the new value in the message field at the bottom of the window */

        [cself.messageText setStringValue: [NSString stringWithJSValue: value fromContext: ctx]];

            /* return success */

        theResult = true;

    }

    return theResult;

}

    /* getter callback for the 'title' property */

static JSValueRef browserTitle( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

        /* return the main window's title */

    return JSValueMakeString( ctx, [[cself.browserWindow title] jsStringValue] );

}

    /* setter callback for the 'title' property */

static bool browserSetTitle( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef value, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

    bool theResult = false;

        /* verify that the new value is of the proper type */

    if ( JSValueIsString( ctx, value ) ) {

            /* set the main browser window's title */

        [cself.browserWindow setTitle: [NSString stringWithJSValue: value fromContext: ctx]];

            /* return success */

        theResult = true;

    }

    return theResult;

}

    /* getter callback for the 'url' property */

static JSValueRef browserURL( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

        /* return the text from the url field at the top of the

        browser window */

    return JSValueMakeString( ctx, [[cself.theURL stringValue] jsStringValue] );

}

    /* setter callback for the 'url' property */

static bool browserSetURL( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef value, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

    bool theResult = false;

        /* verify that the new value is of the proper type */

    if ( JSValueIsString( ctx, value ) ) {

            /* set the text from the url field at the top of the

            browser window */

        [cself.theURL setStringValue: [NSString stringWithJSValue: value fromContext: ctx] ];

            /* return success */

        theResult = true;

    }

    return theResult;

}

    /* getter callback for the 'backlink' property */

static JSValueRef browserBackLink( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

    JSValueRef theResult = NULL;

        /* if there is a back item in the WebView's history list,

        then return the url for that item, otherwise return null. */

    WebHistoryItem *backItem = [[cself.theWebView backForwardList] backItem ];

    if ( backItem ) {

        theResult = JSValueMakeString( ctx, [[backItem URLString] jsStringValue] );

    } else {

        theResult = JSValueMakeNull( ctx );

    }

    return theResult;

}

    /* getter callback for the 'forwardlink' property */

static JSValueRef browserForwardLink( JSContextRef ctx, JSObjectRef object,

            JSStringRef propertyName, JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( object );

    JSValueRef theResult = NULL;

        /* if there is a forward item in the WebView's history list,

        then return the url for that item, otherwise return null. */

    WebHistoryItem *forwardItem = [[cself.theWebView backForwardList] forwardItem ];

    if ( forwardItem ) {

        theResult = JSValueMakeString( ctx, [[forwardItem URLString] jsStringValue] );

    } else {

        theResult = JSValueMakeNull( ctx );

    }

    return theResult;

}

    /* browserStaticValues contains the list of value properties

    defined for the browser class.  Each entry in the list includes the

    property name, a pointer to a getter callback (or NULL), a pointer

    to a setter callback (or NULL),  and some attribute flags.  Getters

    and setters for the property values are defined above.  

    Note we have set the attributes to both kJSPropertyAttributeDontDelete

    and kJSPropertyAttributeReadOnly.  These attributes are to prevent

    wayward scripts from removing or, in some cases, changing these values. */

static JSStaticValue browserStaticValues[] = {

    { "progress", browserProgress, browserSetProgress, kJSPropertyAttributeDontDelete },

    { "loading", browserLoading, NULL, kJSPropertyAttributeDontDelete | kJSPropertyAttributeReadOnly },

    { "message", browserMessage, browserSetMessage, kJSPropertyAttributeDontDelete },

    { "title", browserTitle, browserSetTitle, kJSPropertyAttributeDontDelete },

    { "url", browserURL, browserSetURL, kJSPropertyAttributeDontDelete },

    { "backlink", browserBackLink, NULL, kJSPropertyAttributeDontDelete | kJSPropertyAttributeReadOnly },

    { "forwardlink", browserForwardLink, NULL, kJSPropertyAttributeDontDelete | kJSPropertyAttributeReadOnly },

    { 0, 0, 0, 0 }

};

    /* function callback for the 'load' property */

static JSValueRef browserLoad( JSContextRef ctx, JSObjectRef function,

            JSObjectRef thisObject, size_t argumentCount,

            const JSValueRef arguments[], JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( thisObject );

        /* if there is at least one argument to the function and it is a string... */

    if ( ( argumentCount >= 1 ) && JSValueIsString( ctx, arguments[0] ) ) {

            /* convert the first argument into a url and ask the WebView

            to load the url. */

        [[cself.theWebView mainFrame]

            loadRequest: [NSURLRequest requestWithURL:

                [NSURL URLWithString:

                    [NSString stringWithJSValue: arguments[0] fromContext: ctx]]]];

    }

        /* return null to JavaScript */

    return JSValueMakeNull( ctx );

}

    /* function callback for the 'back' property */

static JSValueRef browserBack( JSContextRef ctx, JSObjectRef function,

            JSObjectRef thisObject, size_t argumentCount,

            const JSValueRef arguments[], JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( thisObject );

        /* add all of the parameters into an NSArray as strings */

    [cself.theWebView goBack];

        /* return null to JavaScript */

    return JSValueMakeNull( ctx );

}

    /* function callback for the 'forward' property */

static JSValueRef browserForward( JSContextRef ctx, JSObjectRef function,

            JSObjectRef thisObject, size_t argumentCount,

            const JSValueRef arguments[], JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( thisObject );

        /* add all of the parameters into an NSArray as strings */

    [cself.theWebView goForward];

        /* return null to JavaScript */

    return JSValueMakeNull( ctx );

}

    /* function callback for the 'eval' property */

static JSValueRef browserEvaluateScript( JSContextRef ctx, JSObjectRef function,

            JSObjectRef thisObject, size_t argumentCount,

            const JSValueRef arguments[], JSValueRef *exception ) {

        /* a reference to the Controller object was stored in

        the private data field for the object when it was created. */

    Controller *cself = (Controller *) JSObjectGetPrivate( thisObject );

    JSValueRef theResult = NULL;

    static int bEvalLevel = 0; /* guard against infinite recursion */

    const int bEvalMax = 20;

        /* add all of the parameters into an NSArray as strings */

    if ( ( argumentCount >= 1 ) && JSValueIsString( ctx, arguments[0] ) && ( bEvalLevel < bEvalMax ) ) {

            /* increment recursion guard counter */

        bEvalLevel++;

            /* get the argument as a string */

        JSStringRef theScript = JSValueToStringCopy( ctx, arguments[0], NULL );

        if ( theScript != NULL ) {

                /* get the argument as a string */

            JSGlobalContextRef webViewContext = [[cself.theWebView mainFrame] globalContext];

                /* evaluate the string in the browser's context */

            JSValueRef result = JSEvaluateScript( webViewContext, theScript, NULL, NULL, 0, NULL );

                /* copy the result over to the calling context. */

            if ( result != NULL ) {

                    /* if we're calling from the webView's context, simply return the

                    result.  It's okay to do so because the result object is already

                    in the correct context. */

                if ( ctx == webViewContext ) {

                    theResult = result;

                } else {

                        /* value reference for returned by the script is in a different

                        context than the calling context so we need to transfer it over

                        to the caller's context  */

                    if ( JSValueIsString( webViewContext, result ) ) {

                        JSStringRef stringResult = JSValueToStringCopy( webViewContext, result, NULL );

                        if ( stringResult != NULL ) {

                            theResult = JSValueMakeString( ctx, stringResult );

                            JSStringRelease( stringResult );

                        }

                    } else if ( JSValueIsNumber( webViewContext, result ) ) {

                        theResult = JSValueMakeNumber( ctx, JSValueToNumber( webViewContext, result, NULL ) );

                    } else if ( JSValueIsBoolean( webViewContext, result ) ) {

                        theResult = JSValueMakeBoolean( ctx, JSValueToBoolean( webViewContext, result ) );

                    } else if ( JSValueIsNull( webViewContext, result ) ) {

                        theResult = JSValueMakeNull( ctx );

                    } else {

                        theResult = JSValueMakeUndefined( ctx );

                    }

                }

            }

            JSStringRelease( theScript );

        }

            /* decrement recursion guard counter */

        --bEvalLevel;

    }

        /* return the result, or null if none found */

    return ( ( theResult != NULL ) ? theResult : JSValueMakeNull( ctx ) );

}

    /* browserStaticFunctions contains the list of function properties

    defined for the browser class.  Each entry in the list includes the

    property name, a pointer to the associated callback (defined above),

    and some attribute flags.  It is a zero terminated list with the last

    entry set to all zeros.

    Note we have set the attributes to both kJSPropertyAttributeDontDelete

    and kJSPropertyAttributeReadOnly.  These attributes are to prevent

    wayward scripts from changing or removing these values. */

static JSStaticFunction browserStaticFunctions[] = {

    { "load", browserLoad, kJSPropertyAttributeDontDelete | kJSPropertyAttributeReadOnly },

    { "back", browserBack, kJSPropertyAttributeDontDelete | kJSPropertyAttributeReadOnly },

    { "forward", browserForward, kJSPropertyAttributeDontDelete | kJSPropertyAttributeReadOnly },

    { "eval", browserEvaluateScript, kJSPropertyAttributeDontDelete | kJSPropertyAttributeReadOnly },

    { 0, 0, 0 }

};

    /* BrowserClass returns a JavaScriptCore class reference that you can use

    for creating objects manipulating the browser window.  This class also

    contains methods for executing scripts in the WebView's JavaScript

    context.

    Objects defined by this class have the following properties

    and methods that can be accessed from JavaScripts in both the

    Controller's JavaScript and from inside of scripts running

    in the WebView displayed in the browser window.

    properties:

        progress (boolean, read/write) - set to true to display the animated progress bar

        loading (boolean, read only) - true while loading a page

        message (string, read/write) - status message displayed at the bottom of the window

        title (string, read/write) - the window's title

        url (string, read/write) - the contents of the url field

        backlink (string or null, read only) - url from the history to the next page back (if there is one)

        forwardlink (string, read only) - url from the history to the next page forward (if there is one)

    methods:

        load( url ) - load the url in the WebView

        back() - if there is a back link in the history, go to that link.

        forward() - if there is a forward link in the history, go to that link.

        eval( string ) - evaluate the javascript in the string in the

                WebView's JavaScript context.    Returns the value

                returned by the script (strings, numbers, and booleans only).

    */

JSClassRef BrowserClass( void ) {

        /* we only need one definition for this class, so we cache the

        result between calls. */

    static JSClassRef browserClass = NULL;

    if ( browserClass == NULL ) {

            /* initialize the class definition structure.  It contains

            a lot of procedure pointers, so this step is very important. */

        JSClassDefinition browserClassDefinition = kJSClassDefinitionEmpty;

            /* set the pointers to our static values and functions */

        browserClassDefinition.staticValues = browserStaticValues;

        browserClassDefinition.staticFunctions = browserStaticFunctions;

            /* create the class */

        browserClass = JSClassCreate( &browserClassDefinition );

    }

    return browserClass;

}