impressive API

2 files changed, 226 insertions, 186 deletions

diff --git a/index.html b/index.html
index 65bc93c..716b492 100644
--- a/index.html
+++ b/index.html
@@ -286,6 +286,7 @@
     
 -->
 <script src="js/impress.js"></script>
+<script>impress();</script>
 
 </body>
 </html>
diff --git a/js/impress.js b/js/impress.js
index 34339f5..0e810a6 100644
--- a/js/impress.js
+++ b/js/impress.js
@@ -86,7 +86,13 @@
     
     var scale = function ( s ) {
         return " scale(" + s + ") ";
-    }
+    };
+    
+    var getElementFromUrl = function () {
+        // get id from url # by removing `#` or `#/` from the beginning,
+        // so both "fallback" `#slide-id` and "enhanced" `#/slide-id` will work
+        return byId( window.location.hash.replace(/^#\/?/,"") );
+    };
     
     // CHECK SUPPORT
     
@@ -94,223 +100,255 @@
     var impressSupported = ( pfx("perspective") != null ) &&
                            ( ua.search(/(iphone)|(ipod)|(ipad)|(android)/) == -1 );
     
-    // DOM ELEMENTS
-    
-    var impress = byId("impress");
-    
-    if (!impressSupported) {
-        impress.className = "impress-not-supported";
-        return;
-    } else {
-        impress.className = "";
-    }
-    
-    var canvas = document.createElement("div");
-    canvas.className = "canvas";
-    
-    arrayify( impress.childNodes ).forEach(function ( el ) {
-        canvas.appendChild( el );
-    });
-    impress.appendChild(canvas);
-    
-    var steps = $$(".step", impress);
-    
-    // SETUP
-    // set initial values and defaults
+    var roots = {};
     
-    document.documentElement.style.height = "100%";
-    
-    css(document.body, {
-        height: "100%",
-        overflow: "hidden"
-    });
+    var impress = window.impress = function ( rootId ) {
 
-    var props = {
-        position: "absolute",
-        transformOrigin: "top left",
-        transition: "all 0s ease-in-out",
-        transformStyle: "preserve-3d"
-    }
-    
-    css(impress, props);
-    css(impress, {
-        top: "50%",
-        left: "50%",
-        perspective: "1000px"
-    });
-    css(canvas, props);
-    
-    var current = {
-        translate: { x: 0, y: 0, z: 0 },
-        rotate:    { x: 0, y: 0, z: 0 },
-        scale:     1
-    };
-
-    var stepData = {};
-    
-    steps.forEach(function ( el, idx ) {
-        var data = el.dataset,
-            step = {
-                translate: {
-                    x: data.x || 0,
-                    y: data.y || 0,
-                    z: data.z || 0
-                },
-                rotate: {
-                    x: data.rotateX || 0,
-                    y: data.rotateY || 0,
-                    z: data.rotateZ || data.rotate || 0
-                },
-                scale: data.scale || 1,
-                el: el
-            };
+        rootId = rootId || "impress";
         
-        if ( !el.id ) {
-            el.id = "step-" + (idx + 1);
+        // if already initialized just return the API
+        if (roots["impress-root-" + rootId]) {
+            return roots["impress-root-" + rootId];
         }
         
-        stepData["impress-" + el.id] = step;
+        // DOM ELEMENTS
         
-        css(el, {
-            position: "absolute",
-            transform: "translate(-50%,-50%)" +
-                       translate(step.translate) +
-                       rotate(step.rotate) +
-                       scale(step.scale),
-            transformStyle: "preserve-3d"
-        });
+        var root = byId( rootId );
         
-    });
-
-    // making given step active
-
-    var active = null;
-    var hashTimeout = null;
-    
-    var isStep = function ( el ) {
-        return !!(el && el.id && stepData["impress-" + el.id]);
-    }
-    
-    var select = function ( el ) {
-        if ( !el || !isStep(el) || el == active) {
-            // selected element is not defined as step or is already active
-            return false;
+        if (!impressSupported) {
+            root.className = "impress-not-supported";
+            return;
+        } else {
+            root.className = "";
         }
         
-        // Sometimes it's possible to trigger focus on first link with some keyboard action.
-        // Browser in such a case tries to scroll the page to make this element visible
-        // (even that body overflow is set to hidden) and it breaks our careful positioning.
-        //
-        // So, as a lousy (and lazy) workaround we will make the page scroll back to the top
-        // whenever slide is selected
-        //
-        // If you are reading this and know any better way to handle it, I'll be glad to hear about it!
-        window.scrollTo(0, 0);
+        var canvas = document.createElement("div");
+        canvas.className = "canvas";
         
-        var step = stepData["impress-" + el.id];
+        arrayify( root.childNodes ).forEach(function ( el ) {
+            canvas.appendChild( el );
+        });
+        root.appendChild(canvas);
         
-        if ( active ) {
-            active.classList.remove("active");
-        }
-        el.classList.add("active");
+        var steps = $$(".step", root);
         
-        impress.className = "step-" + el.id;
+        // SETUP
+        // set initial values and defaults
         
-        // `#/step-id` is used instead of `#step-id` to prevent default browser
-        // scrolling to element in hash
-        //
-        // and it has to be set after animation finishes, because in chrome it
-        // causes transtion being laggy
-        window.clearTimeout( hashTimeout );
-        hashTimeout = window.setTimeout(function () {
-            window.location.hash = "#/" + el.id;
-        }, 1000);
+        document.documentElement.style.height = "100%";
         
-        var target = {
-            rotate: {
-                x: -parseInt(step.rotate.x, 10),
-                y: -parseInt(step.rotate.y, 10),
-                z: -parseInt(step.rotate.z, 10)
-            },
-            translate: {
-                x: -step.translate.x,
-                y: -step.translate.y,
-                z: -step.translate.z
-            },
-            scale: 1 / parseFloat(step.scale)
-        };
+        css(document.body, {
+            height: "100%",
+            overflow: "hidden"
+        });
+
+        var props = {
+            position: "absolute",
+            transformOrigin: "top left",
+            transition: "all 0s ease-in-out",
+            transformStyle: "preserve-3d"
+        }
         
-        // check if the transition is zooming in or not
-        var zoomin = target.scale >= current.scale;
+        css(root, props);
+        css(root, {
+            top: "50%",
+            left: "50%",
+            perspective: "1000px"
+        });
+        css(canvas, props);
         
-        // if presentation starts (nothing is active yet)
-        // don't animate (set duration to 0)
-        var duration = (active) ? "1s" : "0";
+        var current = {
+            translate: { x: 0, y: 0, z: 0 },
+            rotate:    { x: 0, y: 0, z: 0 },
+            scale:     1
+        };
+
+        var stepData = {};
         
-        css(impress, {
-            // to keep the perspective look similar for different scales
-            // we need to 'scale' the perspective, too
-            perspective: step.scale * 1000 + "px",
-            transform: scale(target.scale),
-            transitionDuration: duration,
-            transitionDelay: (zoomin ? "500ms" : "0ms")
-        });
+        var isStep = function ( el ) {
+            return !!(el && el.id && stepData["impress-" + el.id]);
+        }
         
-        css(canvas, {
-            transform: rotate(target.rotate, true) + translate(target.translate),
-            transitionDuration: duration,
-            transitionDelay: (zoomin ? "0ms" : "500ms")
+        steps.forEach(function ( el, idx ) {
+            var data = el.dataset,
+                step = {
+                    translate: {
+                        x: data.x || 0,
+                        y: data.y || 0,
+                        z: data.z || 0
+                    },
+                    rotate: {
+                        x: data.rotateX || 0,
+                        y: data.rotateY || 0,
+                        z: data.rotateZ || data.rotate || 0
+                    },
+                    scale: data.scale || 1,
+                    el: el
+                };
+            
+            if ( !el.id ) {
+                el.id = "step-" + (idx + 1);
+            }
+            
+            stepData["impress-" + el.id] = step;
+            
+            css(el, {
+                position: "absolute",
+                transform: "translate(-50%,-50%)" +
+                           translate(step.translate) +
+                           rotate(step.rotate) +
+                           scale(step.scale),
+                transformStyle: "preserve-3d"
+            });
+            
         });
+
+        // making given step active
+
+        var active = null;
+        var hashTimeout = null;
         
-        current = target;
-        active = el;
+        var goto = function ( el ) {
+            if ( !isStep(el) || el == active) {
+                // selected element is not defined as step or is already active
+                return false;
+            }
+            
+            // Sometimes it's possible to trigger focus on first link with some keyboard action.
+            // Browser in such a case tries to scroll the page to make this element visible
+            // (even that body overflow is set to hidden) and it breaks our careful positioning.
+            //
+            // So, as a lousy (and lazy) workaround we will make the page scroll back to the top
+            // whenever slide is selected
+            //
+            // If you are reading this and know any better way to handle it, I'll be glad to hear about it!
+            window.scrollTo(0, 0);
+            
+            var step = stepData["impress-" + el.id];
+            
+            if ( active ) {
+                active.classList.remove("active");
+            }
+            el.classList.add("active");
+            
+            root.className = "step-" + el.id;
+            
+            // `#/step-id` is used instead of `#step-id` to prevent default browser
+            // scrolling to element in hash
+            //
+            // and it has to be set after animation finishes, because in chrome it
+            // causes transtion being laggy
+            window.clearTimeout( hashTimeout );
+            hashTimeout = window.setTimeout(function () {
+                window.location.hash = "#/" + el.id;
+            }, 1000);
+            
+            var target = {
+                rotate: {
+                    x: -parseInt(step.rotate.x, 10),
+                    y: -parseInt(step.rotate.y, 10),
+                    z: -parseInt(step.rotate.z, 10)
+                },
+                translate: {
+                    x: -step.translate.x,
+                    y: -step.translate.y,
+                    z: -step.translate.z
+                },
+                scale: 1 / parseFloat(step.scale)
+            };
+            
+            // check if the transition is zooming in or not
+            var zoomin = target.scale >= current.scale;
+            
+            // if presentation starts (nothing is active yet)
+            // don't animate (set duration to 0)
+            var duration = (active) ? "1s" : "0";
+            
+            css(root, {
+                // to keep the perspective look similar for different scales
+                // we need to 'scale' the perspective, too
+                perspective: step.scale * 1000 + "px",
+                transform: scale(target.scale),
+                transitionDuration: duration,
+                transitionDelay: (zoomin ? "500ms" : "0ms")
+            });
+            
+            css(canvas, {
+                transform: rotate(target.rotate, true) + translate(target.translate),
+                transitionDuration: duration,
+                transitionDelay: (zoomin ? "0ms" : "500ms")
+            });
+            
+            current = target;
+            active = el;
+            
+            return el;
+        };
         
-        return el;
-    };
-    
-    var selectPrev = function () {
-        var prev = steps.indexOf( active ) - 1;
-        prev = prev >= 0 ? steps[ prev ] : steps[ steps.length-1 ];
+        var prev = function () {
+            var prev = steps.indexOf( active ) - 1;
+            prev = prev >= 0 ? steps[ prev ] : steps[ steps.length-1 ];
+            
+            return goto(prev);
+        };
         
-        return select(prev);
-    };
-    
-    var selectNext = function () {
-        var next = steps.indexOf( active ) + 1;
-        next = next < steps.length ? steps[ next ] : steps[ 0 ];
+        var next = function () {
+            var next = steps.indexOf( active ) + 1;
+            next = next < steps.length ? steps[ next ] : steps[ 0 ];
+            
+            return goto(next);
+        };
         
-        return select(next);
-    };
-    
-    // EVENTS
+        window.addEventListener("hashchange", function () {
+            goto( getElementFromUrl() );
+        }, false);
+        
+        // START 
+        // by selecting step defined in url or first step of the presentation
+        goto(getElementFromUrl() || steps[0]);
+
+        return (roots[ "impress-root-" + rootId ] = {
+            goto: goto,
+            next: next,
+            prev: prev
+        });
+
+    }
+})(document, window);
+
+// EVENTS
+
+(function ( document, window ) {
+    'use strict';
     
+    // keyboard navigation handler
     document.addEventListener("keydown", function ( event ) {
         if ( event.keyCode == 9 || ( event.keyCode >= 32 && event.keyCode <= 34 ) || (event.keyCode >= 37 && event.keyCode <= 40) ) {
             switch( event.keyCode ) {
                 case 33: ; // pg up
                 case 37: ; // left
                 case 38:   // up
-                         selectPrev();
+                         impress().prev();
                          break;
                 case 9:  ; // tab
                 case 32: ; // space
                 case 34: ; // pg down
                 case 39: ; // right
                 case 40:   // down
-                         selectNext();
+                         impress().next();
                          break;
             }
             
             event.preventDefault();
         }
     }, false);
-
+    
+    // delegated handler for clicking on the links to presentation steps
     document.addEventListener("click", function ( event ) {
         // event delegation with "bubbling"
-        // check if event target (or any of its parents is a link or a step)
+        // check if event target (or any of its parents is a link)
         var target = event.target;
         while ( (target.tagName != "A") &&
-                (!isStep(target)) &&
                 (target != document.body) ) {
             target = target.parentNode;
         }
@@ -320,28 +358,29 @@
             
             // if it's a link to presentation step, target this step
             if ( href && href[0] == '#' ) {
-                target = byId( href.slice(1) );
+                target = document.getElementById( href.slice(1) );
             }
         }
         
-        if ( select(target) ) {
+        if ( impress().goto(target) ) {
+            event.stopImmediatePropagation();
             event.preventDefault();
         }
     }, false);
     
-    var getElementFromUrl = function () {
-        // get id from url # by removing `#` or `#/` from the beginning,
-        // so both "fallback" `#slide-id` and "enhanced" `#/slide-id` will work
-        return byId( window.location.hash.replace(/^#\/?/,"") );
-    }
-    
-    window.addEventListener("hashchange", function () {
-        select( getElementFromUrl() );
+    // delegated handler for clicking on step elements
+    document.addEventListener("click", function ( event ) {
+        var target = event.target;
+        // find closest step element
+        while ( !target.classList.contains("step") &&
+                (target != document.body) ) {
+            target = target.parentNode;
+        }
+        
+        if ( impress().goto(target) ) {
+            event.preventDefault();
+        }
     }, false);
     
-    // START 
-    // by selecting step defined in url or first step of the presentation
-    select(getElementFromUrl() || steps[0]);
-    
 })(document, window);