From 821413607a0718156f9d25d895e89b1c3d37aa8b Mon Sep 17 00:00:00 2001
From: Daniel Narvaez <dwnarvaez@gmail.com>
Date: Wed, 06 Feb 2013 13:49:14 +0000
Subject: Copy various bits from gaia

---
(limited to 'apps/system/camera/js/filmstrip.js')

diff --git a/apps/system/camera/js/filmstrip.js b/apps/system/camera/js/filmstrip.js
new file mode 100644
index 0000000..d428801
--- /dev/null
+++ b/apps/system/camera/js/filmstrip.js
@@ -0,0 +1,568 @@
+/*
+ * filmstrip.js: filmstrip, thumbnails and previews for the camera.
+ */
+
+'use strict';
+
+var Filmstrip = (function() {
+
+  // This array holds all the data we need for image and video previews
+  var items = [];
+  var currentItemIndex;
+
+  // Maximum number of thumbnails in the filmstrip
+  var MAX_THUMBNAILS = 5;
+  var THUMBNAIL_WIDTH = 46;  // size of each thumbnail
+  var THUMBNAIL_HEIGHT = 46;
+
+  // Timer for auto-hiding the filmstrip
+  var hideTimer = null;
+
+  // Document elements we care about
+  var filmstrip = document.getElementById('filmstrip');
+  var preview = document.getElementById('preview');
+  var frameContainer = document.getElementById('frame-container');
+  var mediaFrame = document.getElementById('media-frame');
+  var cameraButton = document.getElementById('camera-button');
+  var shareButton = document.getElementById('share-button');
+  var deleteButton = document.getElementById('delete-button');
+  var filmstripGalleryButton =
+    document.getElementById('filmstrip-gallery-button');
+
+  // Offscreen elements for generating thumbnails with
+  var offscreenImage = new Image();
+  var offscreenVideo = document.createElement('video');
+
+  // Set up event handlers
+  cameraButton.onclick = returnToCameraMode;
+  deleteButton.onclick = deleteCurrentItem;
+  shareButton.onclick = shareCurrentItem;
+  filmstripGalleryButton.onclick = Camera.galleryBtnPressed;
+  mediaFrame.addEventListener('dbltap', handleDoubleTap);
+  mediaFrame.addEventListener('transform', handleTransform);
+  mediaFrame.addEventListener('pan', handlePan);
+  mediaFrame.addEventListener('swipe', handleSwipe);
+
+  // Generate gesture events
+  var gestureDetector = new GestureDetector(mediaFrame);
+  gestureDetector.startDetecting();
+
+  // Create the MediaFrame for previews
+  var frame = new MediaFrame(mediaFrame);
+
+  // Start off with it positioned correctly.
+  setOrientation(Camera._phoneOrientation);
+
+  // If we're running in secure mode, we never want the user to see the
+  // gallery button or the share button.
+  filmstrip.removeChild(filmstripGalleryButton);
+  shareButton.parentNode.removeChild(shareButton);
+
+  function isShown() {
+    return !filmstrip.classList.contains('hidden');
+  }
+
+  function hide() {
+    filmstrip.classList.add('hidden');
+    if (hideTimer) {
+      clearTimeout(hideTimer);
+      hideTimer = null;
+    }
+  }
+
+  /*
+   * With a time, show the filmstrip and then hide it after the time is up.
+   * Without time, show until hidden.
+   * Tapping in the camera toggles it. And if toggled on, it will be on
+   * without a timer.
+   * It is always on when a preview is shown.
+   * After recording a photo or video, it is shown for 5 seconds.
+   * And it is also shown for 5 seconds after leaving preview mode.
+   */
+  function show(time) {
+    filmstrip.classList.remove('hidden');
+    if (hideTimer) {
+      clearTimeout(hideTimer);
+      hideTimer = null;
+    }
+    if (time)
+      hideTimer = setTimeout(hide, time);
+  }
+
+  filmstrip.onclick = function(event) {
+    var target = event.target;
+    if (!target || !target.classList.contains('thumbnail'))
+      return;
+
+    var index = parseInt(target.dataset.index);
+    previewItem(index);
+    // If we're showing previews be sure we're showing the filmstrip
+    // with no timeout and be sure that the viewfinder video is paused.
+    show();
+    Camera.viewfinder.pause();
+    // If there is a preview shown, we want the gallery button in
+    // the filmstrip
+    filmstripGalleryButton.classList.remove('hidden');
+  };
+
+  function previewItem(index) {
+    // Don't redisplay the item if it is already displayed
+    if (currentItemIndex === index)
+      return;
+
+    var item = items[index];
+
+    if (item.isImage) {
+      frame.displayImage(item.blob, item.width, item.height, item.preview);
+    }
+    else if (item.isVideo) {
+      frame.displayVideo(item.blob, item.width, item.height, item.rotation);
+    }
+
+    preview.classList.remove('offscreen');
+    currentItemIndex = index;
+
+    // Highlight the border of the thumbnail we're previewing
+    // and clear the highlight on all others
+    items.forEach(function(item, itemindex) {
+      if (itemindex === index)
+        item.element.classList.add('previewed');
+      else
+        item.element.classList.remove('previewed');
+    });
+  }
+
+  function returnToCameraMode() {
+    Camera.viewfinder.play();        // Restart the viewfinder
+    show(Camera.FILMSTRIP_DURATION); // Fade the filmstrip after a delay
+    // hide the gallery button in the filmstrip
+    filmstripGalleryButton.classList.add('hidden');
+    preview.classList.add('offscreen');
+    frame.clear();
+    if (items.length > 0)
+      items[currentItemIndex].element.classList.remove('previewed');
+    currentItemIndex = null;
+   }
+
+  function deleteCurrentItem() {
+    var item = items[currentItemIndex];
+    var msg, storage, filename;
+
+    if (item.isImage) {
+      msg = navigator.mozL10n.get('delete-photo?');
+      storage = Camera._pictureStorage;
+      filename = item.filename;
+    }
+    else {
+      msg = navigator.mozL10n.get('delete-video?');
+      storage = Camera._videoStorage;
+      filename = item.filename;
+    }
+
+    // The system app is not allowed to use confirm, I think
+    // so if we're running in secure mode, just delete the file without
+    // confirmation
+    if (Camera._secureMode || confirm(msg)) {
+      // Remove the item from the array of items
+      items.splice(currentItemIndex, 1);
+
+      // Remove the thumbnail image from the filmstrip
+      filmstrip.removeChild(item.element);
+      URL.revokeObjectURL(item.element.src);
+
+      // Renumber the item elements
+      items.forEach(function(item, index) {
+        item.element.dataset.index = index;
+      });
+
+      // If there are no more items, go back to the camera
+      if (items.length === 0) {
+        returnToCameraMode();
+      }
+      else {
+        // Otherwise, switch the frame to display the next item. But if
+        // we just deleted the last item, then we'll need to display the
+        // previous item.
+        var newindex = currentItemIndex;
+        if (newindex >= items.length)
+          newindex = items.length - 1;
+        currentItemIndex = null;
+        previewItem(newindex);
+      }
+
+      // Actually delete the file
+      storage.delete(filename).onerror = function(e) {
+        console.warn('Failed to delete', filename,
+                     'from DeviceStorage:', e.target.error);
+      }
+    }
+  }
+
+  function shareCurrentItem() {
+    if (Camera._secureMode)
+      return;
+    var item = items[currentItemIndex];
+    var type = item.isImage ? 'image/*' : 'video/*';
+    var nameonly = item.filename.substring(item.filename.lastIndexOf('/') + 1);
+    var activity = new MozActivity({
+      name: 'share',
+      data: {
+        type: type,
+        number: 1,
+        blobs: [item.blob],
+        filenames: [nameonly],
+        filepaths: [item.filename] /* temporary hack for bluetooth app */
+      }
+    });
+    activity.onerror = function(e) {
+      console.warn('Share activity error:', activity.error.name);
+    }
+  }
+
+  function handleDoubleTap(e) {
+    if (!items[currentItemIndex].isImage)
+      return;
+
+    var scale;
+    if (frame.fit.scale > frame.fit.baseScale)
+      scale = frame.fit.baseScale / frame.fit.scale;
+    else
+      scale = 2;
+
+    // If the phone orientation is 0 (unrotated) then the gesture detector's
+    // event coordinates match what's on the screen, and we use them to
+    // specify a point to zoom in or out on. For other orientations we could
+    // calculate the correct point, but instead just use the midpoint.
+    var x, y;
+    if (Camera._phoneOrientation === 0) {
+      x = e.detail.clientX;
+      y = e.detail.clientY;
+    }
+    else {
+      x = mediaFrame.offsetWidth / 2;
+      y = mediaFrame.offsetHeight / 2;
+    }
+
+    frame.zoom(scale, x, y, 200);
+  }
+
+  function handleTransform(e) {
+    if (!items[currentItemIndex].isImage)
+      return;
+
+    // If the phone orientation is 0 (unrotated) then the gesture detector's
+    // event coordinates match what's on the screen, and we use them to
+    // specify a point to zoom in or out on. For other orientations we could
+    // calculate the correct point, but instead just use the midpoint.
+    var x, y;
+    if (Camera._phoneOrientation === 0) {
+      x = e.detail.midpoint.clientX;
+      y = e.detail.midpoint.clientY;
+    }
+    else {
+      x = mediaFrame.offsetWidth / 2;
+      y = mediaFrame.offsetHeight / 2;
+    }
+
+    frame.zoom(e.detail.relative.scale, x, y);
+  }
+
+  function handlePan(e) {
+    if (!items[currentItemIndex].isImage)
+      return;
+
+    // The gesture detector event does not take our CSS rotation into
+    // account, so we have to pan by a dx and dy that depend on how
+    // the MediaFrame is rotated
+    var dx, dy;
+    switch (Camera._phoneOrientation) {
+    case 0:
+      dx = e.detail.relative.dx;
+      dy = e.detail.relative.dy;
+      break;
+    case 90:
+      dx = -e.detail.relative.dy;
+      dy = e.detail.relative.dx;
+      break;
+    case 180:
+      dx = -e.detail.relative.dx;
+      dy = -e.detail.relative.dy;
+      break;
+    case 270:
+      dx = e.detail.relative.dy;
+      dy = -e.detail.relative.dx;
+      break;
+    }
+
+    frame.pan(dx, dy);
+  }
+
+  function handleSwipe(e) {
+    // Because the stuff around the media frame does not change position
+    // when the phone is rotated, we don't alter these directions based
+    // on orientation. To dismiss the preview, the user always swipes toward
+    // the filmstrip.
+
+    switch (e.detail.direction) {
+    case 'up':   // close the preview if the swipe is fast enough
+      if (e.detail.vy < -1)
+        returnToCameraMode();
+      break;
+    case 'left': // go to next image if fast enough
+      if (e.detail.vx < -1 && currentItemIndex < items.length - 1)
+        previewItem(currentItemIndex + 1);
+      break;
+    case 'right': // go to previous image if fast enough
+      if (e.detail.vx > 1 && currentItemIndex > 0)
+        previewItem(currentItemIndex - 1);
+      break;
+    }
+  }
+
+  function addImage(filename, blob) {
+    parseJPEGMetadata(blob, function getPreviewBlob(metadata) {
+      if (metadata.preview) {
+        var previewBlob = blob.slice(metadata.preview.start,
+                                     metadata.preview.end,
+                                     'image/jpeg');
+
+        offscreenImage.src = URL.createObjectURL(previewBlob);
+        offscreenImage.onload = function() {
+          createThumbnailFromElement(offscreenImage, false, 0,
+                                     function(thumbnail) {
+                                       addItem({
+                                         isImage: true,
+                                         filename: filename,
+                                         thumbnail: thumbnail,
+                                         blob: blob,
+                                         width: metadata.width,
+                                         height: metadata.height,
+                                         preview: metadata.preview
+                                       });
+                                     });
+          URL.revokeObjectURL(offscreenImage.src);
+          offscreenImage.onload = null;
+          offscreenImage.src = null;
+        };
+      }
+    }, function logerr(msg) { console.warn(msg); });
+  }
+
+  function addVideo(filename) {
+    var request = Camera._videoStorage.get(filename);
+    request.onerror = function() {
+      console.warn('addVideo:', filename, request.error.name);
+    };
+    request.onsuccess = function() {
+      var blob = request.result;
+      getVideoRotation(blob, function(rotation) {
+        if (typeof rotation !== 'number') {
+          console.warn('Unexpected rotation:', rotation);
+          rotation = 0;
+        }
+
+        var url = URL.createObjectURL(blob);
+
+        offscreenVideo.preload = 'metadata';
+        offscreenVideo.style.width = THUMBNAIL_WIDTH + 'px';
+        offscreenVideo.style.height = THUMBNAIL_HEIGHT + 'px';
+        offscreenVideo.src = url;
+
+        offscreenVideo.onerror = function() {
+          URL.revokeObjectURL(url);
+          offscreenVideo.onerror = null;
+          offscreenVideo.onloadedmetadata = null;
+          offscreenVideo.removeAttribute('src');
+          offscreenVideo.load();
+          console.warn('not a video file', filename);
+        }
+
+        offscreenVideo.onloadedmetadata = function() {
+          createThumbnailFromElement(offscreenVideo, true, rotation,
+                                     function(thumbnail) {
+                                       addItem({
+                                         isVideo: true,
+                                         filename: filename,
+                                         thumbnail: thumbnail,
+                                         blob: blob,
+                                         width: offscreenVideo.videoWidth,
+                                         height: offscreenVideo.videoHeight,
+                                         rotation: rotation
+                                       });
+                                     });
+          URL.revokeObjectURL(url);
+          offscreenVideo.onerror = null;
+          offscreenVideo.onloadedmetadata = null;
+          offscreenVideo.removeAttribute('src');
+          offscreenVideo.load();
+        };
+      });
+    };
+  }
+
+  // Add a thumbnail to the filmstrip.
+  // The details object contains everything we need to know
+  // to display the thumbnail and preview the image or video
+  function addItem(item) {
+    // Thumbnails go from most recent to least recent.
+    items.unshift(item);
+
+    // Create an image element for this new thumbnail and display it
+    item.element = new Image();
+    item.element.src = URL.createObjectURL(item.thumbnail);
+    item.element.classList.add('thumbnail');
+    filmstrip.insertBefore(item.element, filmstrip.firstElementChild);
+
+    // If we have too many thumbnails now, remove the oldest one from
+    // the array, and remove its element from the filmstrip and release
+    // its blob url
+    if (items.length > MAX_THUMBNAILS) {
+      var oldest = items.pop();
+      filmstrip.removeChild(oldest.element);
+      URL.revokeObjectURL(oldest.element.src);
+    }
+
+    // Now update the index associated with each of the remaining elements
+    // so that the click event handle knows which one it clicked on
+    items.forEach(function(item, index) {
+      item.element.dataset.index = index;
+    });
+  }
+
+  // Remove all items from the filmstrip. Don't delete the files, but
+  // forget all of our state. This also exits preview mode if we're in it.
+  function clear() {
+    if (!preview.classList.contains('offscreen'))
+      returnToCameraMode();
+    items.forEach(function(item) {
+      filmstrip.removeChild(item.element);
+      URL.revokeObjectURL(item.element.src);
+    });
+    items.length = 0;
+  }
+
+  // Create a thumbnail size canvas, copy the <img> or <video> into it
+  // cropping the edges as needed to make it fit, and then extract the
+  // thumbnail image as a blob and pass it to the callback.
+  function createThumbnailFromElement(elt, video, rotation, callback) {
+    // Create a thumbnail image
+    var canvas = document.createElement('canvas');
+    var context = canvas.getContext('2d');
+    canvas.width = THUMBNAIL_WIDTH;
+    canvas.height = THUMBNAIL_HEIGHT;
+    var eltwidth = video ? elt.videoWidth : elt.width;
+    var eltheight = video ? elt.videoHeight : elt.height;
+    var scalex = canvas.width / eltwidth;
+    var scaley = canvas.height / eltheight;
+
+    // Take the larger of the two scales: we crop the image to the thumbnail
+    var scale = Math.max(scalex, scaley);
+
+    // Calculate the region of the image that will be copied to the
+    // canvas to create the thumbnail
+    var w = Math.round(THUMBNAIL_WIDTH / scale);
+    var h = Math.round(THUMBNAIL_HEIGHT / scale);
+    var x = Math.round((eltwidth - w) / 2);
+    var y = Math.round((eltheight - h) / 2);
+
+    // If a rotation is specified, rotate the canvas context
+    if (rotation) {
+      context.save();
+      switch (rotation) {
+      case 90:
+        context.translate(THUMBNAIL_WIDTH, 0);
+        context.rotate(Math.PI / 2);
+        break;
+      case 180:
+        context.translate(THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT);
+        context.rotate(Math.PI);
+        break;
+      case 270:
+        context.translate(0, THUMBNAIL_HEIGHT);
+        context.rotate(-Math.PI / 2);
+        break;
+      }
+    }
+
+    // Draw that region of the image into the canvas, scaling it down
+    context.drawImage(elt, x, y, w, h,
+                      0, 0, THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT);
+
+    // Restore the default rotation so the play arrow comes out correctly
+    if (rotation) {
+      context.restore();
+    }
+
+    // If this is a video, superimpose a translucent play button over
+    // the captured video frame to distinguish it from a still photo thumbnail
+    if (video) {
+      // First draw a transparent gray circle
+      context.fillStyle = 'rgba(0, 0, 0, .3)';
+      context.beginPath();
+      context.arc(THUMBNAIL_WIDTH / 2, THUMBNAIL_HEIGHT / 2,
+                  THUMBNAIL_HEIGHT / 3, 0, 2 * Math.PI, false);
+      context.fill();
+
+      // Now outline the circle in white
+      context.strokeStyle = 'rgba(255,255,255,.6)';
+      context.lineWidth = 2;
+      context.stroke();
+
+      // And add a white play arrow.
+      context.beginPath();
+      context.fillStyle = 'rgba(255,255,255,.6)';
+      // The height of an equilateral triangle is sqrt(3)/2 times the side
+      var side = THUMBNAIL_HEIGHT / 3;
+      var triangle_height = side * Math.sqrt(3) / 2;
+      context.moveTo(THUMBNAIL_WIDTH / 2 + triangle_height * 2 / 3,
+                     THUMBNAIL_HEIGHT / 2);
+      context.lineTo(THUMBNAIL_WIDTH / 2 - triangle_height / 3,
+                     THUMBNAIL_HEIGHT / 2 - side / 2);
+      context.lineTo(THUMBNAIL_WIDTH / 2 - triangle_height / 3,
+                     THUMBNAIL_HEIGHT / 2 + side / 2);
+      context.closePath();
+      context.fill();
+    }
+
+    canvas.toBlob(callback, 'image/jpeg');
+  }
+
+  function setOrientation(orientation) {
+    preview.dataset.orientation = orientation;
+    filmstrip.dataset.orientation = orientation;
+    mediaFrame.dataset.orientation = orientation;
+
+    // When we rotate the media frame, we also have to change its size
+    var containerWidth = frameContainer.offsetWidth;
+    var containerHeight = frameContainer.offsetHeight;
+    if (orientation === 0 || orientation === 180) {
+      mediaFrame.style.width = containerWidth + 'px';
+      mediaFrame.style.height = containerHeight + 'px';
+      mediaFrame.style.top = 0 + 'px';
+      mediaFrame.style.left = 0 + 'px';
+    }
+    else {
+      mediaFrame.style.width = containerHeight + 'px';
+      mediaFrame.style.height = containerWidth + 'px';
+      mediaFrame.style.top = ((containerHeight - containerWidth) / 2) + 'px';
+      mediaFrame.style.left = ((containerWidth - containerHeight) / 2) + 'px';
+    }
+
+    // And rotate so this new size fills the screen
+    mediaFrame.style.transform = 'rotate(-' + orientation + 'deg)';
+
+    // And we have to resize the frame (and its video player)
+    frame.resize();
+    frame.video.setPlayerSize();
+  }
+
+  return {
+    isShown: isShown,
+    hide: hide,
+    show: show,
+    addImage: addImage,
+    addVideo: addVideo,
+    clear: clear,
+    setOrientation: setOrientation
+  };
+}());
--
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