svelte/src/internal/keyed-each.js

113 lines
2.2 KiB

import { on_outro } from './transitions.js';
export function destroyBlock(block, lookup) {
block.d(1);
lookup[block.key] = null;
}
export function outroAndDestroyBlock(block, lookup) {
on_outro(() => {
destroyBlock(block, lookup);
});
block.o(1);
}
export function fixAndOutroAndDestroyBlock(block, lookup) {
block.f();
outroAndDestroyBlock(block, lookup);
}
export function updateKeyedEach(old_blocks, changed, get_key, dynamic, ctx, list, lookup, node, destroy, create_each_block, next, get_context) {
var o = old_blocks.length;
var n = list.length;
var i = o;
var old_indexes = {};
while (i--) old_indexes[old_blocks[i].key] = i;
var new_blocks = [];
var new_lookup = {};
var deltas = {};
var i = n;
while (i--) {
var child_ctx = get_context(ctx, list, i);
var key = get_key(child_ctx);
var block = lookup[key];
if (!block) {
block = create_each_block(key, child_ctx);
block.c();
} else if (dynamic) {
block.p(changed, child_ctx);
}
new_blocks[i] = new_lookup[key] = block;
if (key in old_indexes) deltas[key] = Math.abs(i - old_indexes[key]);
}
var will_move = {};
var did_move = {};
function insert(block) {
if (block.i) block.i(1);
block.m(node, next);
lookup[block.key] = block;
next = block.first;
n--;
}
while (o && n) {
var new_block = new_blocks[n - 1];
var old_block = old_blocks[o - 1];
var new_key = new_block.key;
var old_key = old_block.key;
if (new_block === old_block) {
// do nothing
next = new_block.first;
o--;
n--;
}
else if (!new_lookup[old_key]) {
// remove old block
destroy(old_block, lookup);
o--;
}
else if (!lookup[new_key] || will_move[new_key]) {
insert(new_block);
}
else if (did_move[old_key]) {
o--;
} else if (deltas[new_key] > deltas[old_key]) {
did_move[new_key] = true;
insert(new_block);
} else {
will_move[old_key] = true;
o--;
}
}
while (o--) {
var old_block = old_blocks[o];
if (!new_lookup[old_block.key]) destroy(old_block, lookup);
}
while (n) insert(new_blocks[n - 1]);
return new_blocks;
}
export function measure(blocks) {
const rects = {};
let i = blocks.length;
while (i--) rects[blocks[i].key] = blocks[i].node.getBoundingClientRect();
return rects;
}