229 lines
9.0 KiB
JavaScript
229 lines
9.0 KiB
JavaScript
function getScrollLink() {
|
|
|
|
var scrollLink = {
|
|
extensionId: "scrollLink",
|
|
extensionName: "Scroll Link",
|
|
optional: true,
|
|
settingsBloc: [
|
|
'<p>Binds together editor and preview scrollbars.</p>',
|
|
'<blockquote class="muted"><b>NOTE:</b>',
|
|
' The mapping between Markdown and HTML is based on the position of the title elements (h1, h2, ...) in the page.',
|
|
' Therefore, if your document does not contain any title, the mapping will be linear and consequently less accurate.',
|
|
'</bloquote>'
|
|
].join("")
|
|
};
|
|
|
|
var msie = /msie/.test(navigator.userAgent.toLowerCase());
|
|
|
|
var mdSectionList = [];
|
|
var htmlSectionList = [];
|
|
function pxToFloat(px) {
|
|
return parseFloat(px.substring(0, px.length - 2));
|
|
}
|
|
var buildSections = _.debounce(function() {
|
|
|
|
// Try to find Markdown sections by looking for titles
|
|
var editorElt = $("#wmd-input");
|
|
mdSectionList = [];
|
|
// This textarea is used to measure sections height
|
|
var textareaElt = $("#md-section-helper");
|
|
// It has to be the same width as wmd-input
|
|
textareaElt.width(editorElt.width());
|
|
// Consider wmd-input top padding (will be used for 1st and last section)
|
|
var padding = pxToFloat(editorElt.css('padding-top'));
|
|
var offset = 0, mdSectionOffset = 0;
|
|
|
|
function addMdSection(sectionText) {
|
|
var sectionHeight = padding;
|
|
if(sectionText !== undefined) {
|
|
textareaElt.val(sectionText);
|
|
if (msie) {
|
|
sectionHeight += textareaElt.prop('scrollHeight') + 6;
|
|
} else {
|
|
sectionHeight += textareaElt.prop('scrollHeight');
|
|
}
|
|
}
|
|
var newSectionOffset = mdSectionOffset + sectionHeight;
|
|
mdSectionList.push({
|
|
startOffset: mdSectionOffset,
|
|
endOffset: newSectionOffset,
|
|
height: sectionHeight,
|
|
length: sectionText == undefined ? 0 : sectionText.length + 1
|
|
});
|
|
mdSectionOffset = newSectionOffset;
|
|
padding = 0;
|
|
}
|
|
// Create MD sections by finding title patterns (excluding gfm blocs)
|
|
var text = editorElt.val() + "\n\n";
|
|
text.replace(/^```.*\n[\s\S]*?\n```|(^.+[ \t]*\n=+[ \t]*\n+|^.+[ \t]*\n-+[ \t]*\n+|^\#{1,6}[ \t]*.+?[ \t]*\#*\n+)/gm, function(match, title, matchOffset) {
|
|
if(title) {
|
|
// We just found a title which means end of the previous section
|
|
// Exclude last \n of the section
|
|
var sectionText = undefined;
|
|
if(matchOffset > offset) {
|
|
sectionText = text.substring(offset, matchOffset - 1);
|
|
}
|
|
addMdSection(sectionText);
|
|
offset = matchOffset;
|
|
}
|
|
return "";
|
|
});
|
|
// Last section
|
|
// Consider wmd-input bottom padding and exclude \n\n previously added
|
|
padding += pxToFloat(editorElt.css('padding-bottom'));
|
|
addMdSection(text.substring(offset, text.length - 2));
|
|
|
|
// Try to find corresponding sections in the preview
|
|
var previewElt = $(".preview-container");
|
|
htmlSectionList = [];
|
|
var htmlSectionOffset = 0;
|
|
var previewScrollTop = previewElt.scrollTop();
|
|
// Each title element is a section separator
|
|
var wmdPreviewTop = $(".preview-container").position().top;
|
|
$("#wmd-preview").children("h1,h2,h3,h4,h5,h6").each(function() {
|
|
// Consider div scroll position and header element top margin
|
|
var newSectionOffset = $(this).position().top - wmdPreviewTop + previewScrollTop + pxToFloat($(this).css('margin-top'));
|
|
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
|
|
lastEditorScrollTop = -10;
|
|
lastPreviewScrollTop = -10;
|
|
isScrollPreview = false;
|
|
runScrollLink();
|
|
}, 500);
|
|
|
|
// -10 to be sure the gap is > 9
|
|
var lastEditorScrollTop = -10;
|
|
var lastPreviewScrollTop = -10;
|
|
var isScrollPreview = false;
|
|
// 每次滑动都会调用
|
|
var runScrollLink = _.debounce(function() {
|
|
if(mdSectionList.length === 0 || mdSectionList.length !== htmlSectionList.length) {
|
|
return;
|
|
}
|
|
var editorElt = $("#wmd-input");
|
|
var editorScrollTop = editorElt.scrollTop();
|
|
var previewElt = $(".preview-container");
|
|
var previewScrollTop = previewElt.scrollTop();
|
|
|
|
function animate(srcScrollTop, srcSectionList, destElt, destSectionList, currentDestScrollTop, callback) {
|
|
// Find the section corresponding to the offset
|
|
var sectionIndex = undefined;
|
|
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;
|
|
var destSection = destSectionList[sectionIndex];
|
|
var destScrollTop = destSection.startOffset + destSection.height * posInSection;
|
|
destScrollTop = _.min([
|
|
destScrollTop,
|
|
destElt.prop('scrollHeight') - destElt.outerHeight()
|
|
]);
|
|
if(Math.abs(destScrollTop - currentDestScrollTop) <= 1) {
|
|
// Skip the animation in case it's not necessary
|
|
callback(currentDestScrollTop);
|
|
return;
|
|
}
|
|
|
|
destElt.animate({
|
|
scrollTop: destScrollTop
|
|
}, 500, function() {
|
|
callback(destScrollTop);
|
|
});
|
|
setTimeout(function() {
|
|
// 仅仅是移动bar而不移动内容
|
|
destElt.slimScroll({ scrollTo: destScrollTop, onlyScrollBar: true});
|
|
}, 500);
|
|
}
|
|
|
|
// Perform the animation if diff > 9px
|
|
// console.log(editorScrollTop , lastEditorScrollTop);
|
|
if(isScrollPreview === false && Math.abs(editorScrollTop - lastEditorScrollTop) > 1) {
|
|
// Animate the preview
|
|
lastEditorScrollTop = editorScrollTop;
|
|
// console.log("--")
|
|
animate(editorScrollTop, mdSectionList, previewElt, htmlSectionList, previewScrollTop, function(destScrollTop) {
|
|
lastPreviewScrollTop = destScrollTop;
|
|
// console.log(previewScrollTop, destScrollTop)
|
|
});
|
|
}
|
|
else if(Math.abs(previewScrollTop - lastPreviewScrollTop) > 1) {
|
|
// Animate the editor
|
|
lastPreviewScrollTop = previewScrollTop;
|
|
animate(previewScrollTop, htmlSectionList, editorElt, mdSectionList, editorScrollTop, function(destScrollTop) {
|
|
lastEditorScrollTop = destScrollTop;
|
|
});
|
|
}
|
|
}, 500);
|
|
|
|
scrollLink.buildSections = function() {
|
|
buildSections();
|
|
};
|
|
|
|
// 触发scroll时调用
|
|
scrollLink.onLayoutCreated = function() {
|
|
$(".preview-container").scroll(function() {
|
|
isScrollPreview = true;
|
|
runScrollLink();
|
|
});
|
|
$("#wmd-input").scroll(function() {
|
|
isScrollPreview = false;
|
|
runScrollLink();
|
|
});
|
|
};
|
|
|
|
scrollLink.onEditorConfigure = function(editor) {
|
|
editor.getConverter().hooks.chain("postConversion", function(text) {
|
|
// To avoid losing scrolling position before elements are fully
|
|
// loaded
|
|
var previewElt = $("#wmd-preview");
|
|
previewElt.height(previewElt.height());
|
|
return text;
|
|
});
|
|
};
|
|
|
|
scrollLink.onPreviewFinished = function() {
|
|
// Now set the correct height
|
|
$("#wmd-preview").height("auto");
|
|
buildSections();
|
|
};
|
|
|
|
scrollLink.getCursorPositionForPageDownUpInFullEditorMode = function(scrollTop) {
|
|
var sectionIndex = undefined;
|
|
var srcSection = _.find(mdSectionList, function(section, index) {
|
|
sectionIndex = index;
|
|
return scrollTop < section.endOffset;
|
|
});
|
|
if(srcSection === undefined) {
|
|
// Something wrong in the algorithm...
|
|
return -1;
|
|
}
|
|
var caretPosition = 0;
|
|
for (var index = 0; index <= sectionIndex; index++) {
|
|
caretPosition = caretPosition + mdSectionList[index].length;
|
|
}
|
|
return caretPosition;
|
|
}
|
|
|
|
return scrollLink;
|
|
}
|
|
|