From 21c73b77c3f8e9d9f2e98debe8e90c434de4efbe Mon Sep 17 00:00:00 2001
From: Danny Yoo <dyoo@cs.wpi.edu>
Date: Mon, 12 Sep 2011 11:43:06 -0400
Subject: [PATCH] adding forward and backward movement

---
 web-world/impl.rkt        |  5 +++
 web-world/js-impl.js      | 94 +++++++++++++++++++++++++++++++++++++++
 web-world/racket-impl.rkt | 22 +++++++++
 3 files changed, 121 insertions(+)

diff --git a/web-world/impl.rkt b/web-world/impl.rkt
index 0d541c1..f0f8b27 100644
--- a/web-world/impl.rkt
+++ b/web-world/impl.rkt
@@ -48,6 +48,11 @@
                     
                     view-down?
                     view-down
+
+                    view-forward?
+                    view-forward
+                    view-backward?
+                    view-backward
                     
                     view-text
                     update-view-text
diff --git a/web-world/js-impl.js b/web-world/js-impl.js
index f5f2ea6..d2a11e1 100644
--- a/web-world/js-impl.js
+++ b/web-world/js-impl.js
@@ -324,6 +324,60 @@
                 view.focus = view.focus.children(':first');
             });
     };
+
+
+    MockView.prototype.forward = function() {
+        return this.act(
+            function(cursor) {
+                return cursor.succ();
+            },
+            function(eventHandlers) {
+                return eventHandlers;
+            },
+            function(view) {
+                if (view.focus.children().length > 0) {
+                    view.focus = view.focus.children(':first');
+                } else if (view.focus.next().length > 0) {
+                    view.focus = view.focus.next();
+                } else {
+                    while (true) {
+                        view.focus = view.focus.parent();
+                        if (view.focus.next().length > 0) {
+                            view.focus = view.focus.next();
+                            return;
+                        }
+                    }
+                }
+            });
+    };
+
+    MockView.prototype.backward = function() {
+        return this.act(
+            function(cursor) {
+                return cursor.pred();
+            },
+            function(eventHandlers) {
+                return eventHandlers;
+            },
+            function(view) {
+                if (view.focus.prev().length > 0) {
+                    view.focus = view.focus.prev();
+                    while (view.focus.children().length > 0) {
+                        view.focus = view.focus.children(':last');
+                    }
+                } else {
+                    view.focus = view.focus.parent();
+                }
+
+            });
+    };
+
+
+
+
+
+
+
     
     var mockViewIdGensym = 0;
 
@@ -489,6 +543,13 @@
         return this.cursor.canRight();
     };
 
+    MockView.prototype.isForwardMovementOk = function() {
+        return this.cursor.canSucc();
+    };
+
+    MockView.prototype.isBackwardMovementOk = function() {
+        return this.cursor.canPred();
+    };
 
 
     //////////////////////////////////////////////////////////////////////
@@ -1620,6 +1681,21 @@
             return view.down();
         });
 
+    EXPORTS['view-forward'] = makePrimitiveProcedure(
+        'view-forward',
+        1,
+        function(MACHINE) {
+            var view = checkMockView(MACHINE, 'view-forward', 0);
+            return view.forward();
+        });
+
+    EXPORTS['view-backward'] = makePrimitiveProcedure(
+        'view-backward',
+        1,
+        function(MACHINE) {
+            var view = checkMockView(MACHINE, 'view-backward', 0);
+            return view.backward();
+        });
 
 
     EXPORTS['view-left?'] = makePrimitiveProcedure(
@@ -1655,6 +1731,24 @@
         });
 
 
+    EXPORTS['view-forward?'] = makePrimitiveProcedure(
+        'view-down?',
+        1,
+        function(MACHINE) {
+            var view = checkMockView(MACHINE, 'view-forward?', 0);
+            return view.isForwardMovementOk();
+        });
+
+    EXPORTS['view-backward?'] = makePrimitiveProcedure(
+        'view-backward?',
+        1,
+        function(MACHINE) {
+            var view = checkMockView(MACHINE, 'view-backward?', 0);
+            return view.isBackwardMovementOk();
+        });
+
+
+
 
 
 
diff --git a/web-world/racket-impl.rkt b/web-world/racket-impl.rkt
index 667ed6b..632132f 100644
--- a/web-world/racket-impl.rkt
+++ b/web-world/racket-impl.rkt
@@ -9,6 +9,12 @@
          view-focus? view-focus
          view-left view-right view-up view-down
          view-left? view-right? view-up? view-down?
+
+         view-forward?
+         view-forward
+         view-backward?
+         view-backward
+         
          view-text update-view-text
          view-attr update-view-attr
          view-css update-view-css
@@ -25,6 +31,9 @@
          view-insert-right
          view-insert-left
 
+
+         
+
          view-remove
          
          open-output-element
@@ -111,6 +120,19 @@
 (define (view-down? v)
   (error 'view-down? "Please run in JavaScript context"))
 
+(define (view-forward? v)
+  (error 'view-forward? "Please run in JavaScript context"))
+
+(define (view-backward? v)
+  (error 'view-backward? "Please run in JavaScript context"))
+
+(define (view-forward v)
+  (error 'view-forward "Please run in JavaScript context"))
+
+(define (view-backward v)
+  (error 'view-backward "Please run in JavaScript context"))
+
+