笙默考试管理系统-MyExamTest----codemirror（38）
目录
insertHeight: function(at, lines, height) {
this.size += lines.length;
this.height += height;
for (var i = 0, e = this.children.length; i < e; ++i) {
var child = this.children[i], sz = child.chunkSize();
if (at <= sz) {
child.insertHeight(at, lines, height);
if (child.lines && child.lines.length > 50) {
while (child.lines.length > 50) {
var spilled = child.lines.splice(child.lines.length - 25, 25);
var newleaf = new LeafChunk(spilled);
child.height -= newleaf.height;
this.children.splice(i + 1, 0, newleaf);
newleaf.parent = this;
}
this.maybeSpill();
}
break;
}
at -= sz;
}
},
maybeSpill: function() {
if (this.children.length <= 10) return;
var me = this;
do {
var spilled = me.children.splice(me.children.length - 5, 5);
var sibling = new BranchChunk(spilled);
if (!me.parent) { // Become the parent node
var copy = new BranchChunk(me.children);
copy.parent = me;
me.children = [copy, sibling];
me = copy;
} else {
me.size -= sibling.size;
me.height -= sibling.height;
var myIndex = indexOf(me.parent.children, me);
me.parent.children.splice(myIndex + 1, 0, sibling);
}
sibling.parent = me.parent;
} while (me.children.length > 10);
me.parent.maybeSpill();
},
iter: function(from, to, op) { this.iterN(from, to - from, op); },
iterN: function(at, n, op) {
for (var i = 0, e = this.children.length; i < e; ++i) {
var child = this.children[i], sz = child.chunkSize();
if (at < sz) {
var used = Math.min(n, sz - at);
if (child.iterN(at, used, op)) return true;
if ((n -= used) == 0) break;
at = 0;
} else at -= sz;
}
}
};
function getLineAt(chunk, n) {
while (!chunk.lines) {
for (var i = 0;; ++i) {
var child = chunk.children[i], sz = child.chunkSize();
if (n < sz) { chunk = child; break; }
n -= sz;
}
}