Stackedit/public/res/extensions/scrollLink.js
2013-12-05 00:25:17 +00:00

323 lines
12 KiB
JavaScript

define([
"jquery",
"underscore",
"classes/Extension",
"text!html/scrollLinkSettingsBlock.html"
], function($, _, Extension, scrollLinkSettingsBlockHTML) {
var scrollLink = new Extension("scrollLink", "Scroll Link", true, true);
scrollLink.settingsBlock = scrollLinkSettingsBlockHTML;
var aceEditor;
scrollLink.onAceCreated = function(aceEditorParam) {
aceEditor = aceEditorParam;
};
var sectionList;
scrollLink.onSectionsCreated = function(sectionListParam) {
sectionList = sectionListParam;
};
var offsetBegin = 0;
scrollLink.onMarkdownTrim = function(offsetBeginParam) {
offsetBegin = offsetBeginParam;
};
var $textareaElt;
var $textareaHelperElt;
var $previewElt;
var mdSectionList = [];
var htmlSectionList = [];
var lastEditorScrollTop;
var lastPreviewScrollTop;
var buildSections = _.debounce(function() {
mdSectionList = [];
var mdTextOffset = 0;
var mdSectionOffset = 0;
var firstSectionOffset = offsetBegin;
function addTextareaSection(sectionText) {
var sectionHeight = 0;
if(sectionText !== undefined) {
$textareaHelperElt.text(sectionText);
sectionHeight += $textareaHelperElt.prop('scrollHeight');
}
var newSectionOffset = mdSectionOffset + sectionHeight;
mdSectionList.push({
startOffset: mdSectionOffset,
endOffset: newSectionOffset,
height: sectionHeight
});
mdSectionOffset = newSectionOffset;
}
if(window.lightMode) {
// Special treatment for light mode
$textareaHelperElt.innerWidth($textareaElt.innerWidth());
_.each(sectionList, function(section, index) {
var sectionText = section.text;
if(index !== sectionList.length - 1) {
if(sectionText.length === 0) {
sectionText = undefined;
}
}
addTextareaSection(sectionText);
});
// Apply a coef to manage divergence in some browsers
var theoricalHeight = _.last(mdSectionList).endOffset;
var realHeight = $textareaElt[0].scrollHeight;
var coef = realHeight/theoricalHeight;
mdSectionList = _.map(mdSectionList, function(mdSection) {
return {
startOffset: mdSection.startOffset * coef,
endOffset: mdSection.endOffset * coef,
height: mdSection.height * coef,
};
});
}
else {
// Everything's much simpler with ACE
_.each(sectionList, function(section) {
mdTextOffset += section.text.length + firstSectionOffset;
firstSectionOffset = 0;
var documentPosition = aceEditor.session.doc.indexToPosition(mdTextOffset);
var screenPosition = aceEditor.session.documentToScreenPosition(documentPosition.row, documentPosition.column);
var newSectionOffset = screenPosition.row * aceEditor.renderer.lineHeight;
var sectionHeight = newSectionOffset - mdSectionOffset;
mdSectionList.push({
startOffset: mdSectionOffset,
endOffset: newSectionOffset,
height: sectionHeight
});
mdSectionOffset = newSectionOffset;
});
}
// Try to find corresponding sections in the preview
htmlSectionList = [];
var htmlSectionOffset;
var previewScrollTop = $previewElt.scrollTop();
$previewElt.find(".preview-content > .se-section-delimiter").each(function() {
if(htmlSectionOffset === undefined) {
// Force start to 0 for the first section
htmlSectionOffset = 0;
return;
}
var $delimiterElt = $(this);
// Consider div scroll position
var newSectionOffset = $delimiterElt.position().top + previewScrollTop;
htmlSectionList.push({
startOffset: htmlSectionOffset,
endOffset: newSectionOffset,
height: newSectionOffset - htmlSectionOffset
});
htmlSectionOffset = newSectionOffset;
});
// Last section
var scrollHeight = $previewElt.prop('scrollHeight');
htmlSectionList.push({
startOffset: htmlSectionOffset,
endOffset: scrollHeight,
height: scrollHeight - htmlSectionOffset
});
// apply Scroll Link (-10 to have a gap > 9px)
lastEditorScrollTop = -10;
lastPreviewScrollTop = -10;
doScrollLink();
}, 500);
var isScrollEditor = false;
var isScrollPreview = false;
var isEditorMoving = false;
var isPreviewMoving = false;
var scrollingHelper = $('<div>');
var doScrollLink = _.throttle(function() {
if(mdSectionList.length === 0 || mdSectionList.length !== htmlSectionList.length) {
// Delay
doScrollLink();
return;
}
var editorScrollTop = window.lightMode ? $textareaElt.scrollTop() : aceEditor.renderer.getScrollTop();
editorScrollTop < 0 && (editorScrollTop = 0);
var previewScrollTop = $previewElt.scrollTop();
function getDestScrollTop(srcScrollTop, srcSectionList, destSectionList) {
// Find the section corresponding to the offset
var sectionIndex;
var srcSection = _.find(srcSectionList, function(section, index) {
sectionIndex = index;
return srcScrollTop < section.endOffset;
});
if(srcSection === undefined) {
// Something wrong in the algorithm...
return;
}
var posInSection = (srcScrollTop - srcSection.startOffset) / (srcSection.height || 1);
var destSection = destSectionList[sectionIndex];
return destSection.startOffset + destSection.height * posInSection;
}
var destScrollTop;
// Perform the animation if diff > 9px
if(isScrollEditor === true) {
if(Math.abs(editorScrollTop - lastEditorScrollTop) <= 9) {
return;
}
isScrollEditor = false;
// Animate the preview
lastEditorScrollTop = editorScrollTop;
destScrollTop = getDestScrollTop(editorScrollTop, mdSectionList, htmlSectionList);
destScrollTop = _.min([
destScrollTop,
$previewElt.prop('scrollHeight') - $previewElt.outerHeight()
]);
if(Math.abs(destScrollTop - previewScrollTop) <= 9) {
// Skip the animation if diff is <= 9
lastPreviewScrollTop = previewScrollTop;
return;
}
$previewElt.stop(true).animate({
scrollTop: destScrollTop
}, {
easing: 'easeOutSine',
duration: 200,
step: function(now) {
isPreviewMoving = true;
lastPreviewScrollTop = previewScrollTop + now;
},
done: function() {
_.defer(function() {
isPreviewMoving = false;
});
},
});
}
else if(isScrollPreview === true) {
if(Math.abs(previewScrollTop - lastPreviewScrollTop) <= 9) {
return;
}
isScrollPreview = false;
// Animate the editor
lastPreviewScrollTop = previewScrollTop;
destScrollTop = getDestScrollTop(previewScrollTop, htmlSectionList, mdSectionList);
if(window.lightMode) {
destScrollTop = _.min([
destScrollTop,
$textareaElt.prop('scrollHeight') - $textareaElt.outerHeight()
]);
}
else {
destScrollTop = _.min([
destScrollTop,
aceEditor.session.getScreenLength() * aceEditor.renderer.lineHeight + aceEditor.renderer.scrollMargin.bottom - aceEditor.renderer.$size.scrollerHeight
]);
// If negative, set it to zero
destScrollTop < 0 && (destScrollTop = 0);
}
if(Math.abs(destScrollTop - editorScrollTop) <= 9) {
// Skip the animation if diff is <= 9
lastEditorScrollTop = editorScrollTop;
return;
}
if(window.lightMode) {
$textareaElt.stop(true).animate({
scrollTop: destScrollTop
}, {
easing: 'easeOutSine',
duration: 200,
step: function(now) {
isEditorMoving = true;
lastEditorScrollTop = editorScrollTop + now;
},
done: function() {
_.defer(function() {
isEditorMoving = false;
});
},
});
}
else {
scrollingHelper.stop(true).css('value', 0).animate({
value: destScrollTop - editorScrollTop
}, {
easing: 'easeOutSine',
duration: 200,
step: function(now) {
isEditorMoving = true;
lastEditorScrollTop = editorScrollTop + now;
aceEditor.session.setScrollTop(lastEditorScrollTop);
},
done: function() {
_.defer(function() {
isEditorMoving = false;
});
},
});
}
}
}, 100);
scrollLink.onLayoutResize = function() {
isScrollEditor = true;
buildSections();
};
scrollLink.onFileClosed = function() {
mdSectionList = [];
};
var scrollAdjust = false;
scrollLink.onReady = function() {
$previewElt = $(".preview-container");
$textareaElt = $("#wmd-input");
// This helper is used to measure sections height in light mode
$textareaHelperElt = $('.textarea-helper');
$previewElt.scroll(function() {
if(isPreviewMoving === false && scrollAdjust === false) {
isScrollPreview = true;
isScrollEditor = false;
doScrollLink();
}
scrollAdjust = false;
});
var handleEditorScroll = function() {
if(isEditorMoving === false) {
isScrollEditor = true;
isScrollPreview = false;
doScrollLink();
}
};
if(window.lightMode) {
$textareaElt.scroll(handleEditorScroll);
}
else {
aceEditor.session.on("changeScrollTop", handleEditorScroll);
}
};
var $previewContentsElt;
scrollLink.onPagedownConfigure = function(editor) {
$previewContentsElt = $("#preview-contents");
editor.getConverter().hooks.chain("postConversion", function(text) {
// To avoid losing scrolling position before elements are fully
// loaded
$previewContentsElt.height($previewContentsElt.height());
return text;
});
};
scrollLink.onPreviewFinished = function() {
// Now set the correct height
var previousHeight = $previewContentsElt.height();
$previewContentsElt.height("auto");
var newHeight = $previewContentsElt.height();
isScrollEditor = true;
if(newHeight < previousHeight) {
// We expect a scroll adjustment
scrollAdjust = true;
}
buildSections();
};
return scrollLink;
});