Skip to content

Handle changes from zero to some items #13

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
May 7, 2018
Merged

Handle changes from zero to some items #13

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
65e2bd0
use tap-diff for reporting
Rich-Harris May 7, 2018
7dceeea
update tests
Rich-Harris May 7, 2018
611afeb
disable tap-diff for now, it is exiting with an error code prematurely
Rich-Harris May 7, 2018
62bc6ac
handle changes from zero to some items
Rich-Harris May 7, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion package.json
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,6 @@
"pretest": "npm run build"
},
"devDependencies": {
"faucet": "^0.0.1",
"port-authority": "^1.0.3",
"puppeteer": "^1.2.0",
"rollup": "^0.58.2",
Expand All @@ -23,6 +22,7 @@
"rollup-plugin-svelte": "^4.1.0",
"serve": "^6.5.3",
"svelte": "^2.1.0",
"tap-diff": "^0.1.1",
"tap-dot": "^1.0.5",
"tape-modern": "^1.0.0"
},
Expand Down
86 changes: 53 additions & 33 deletions src/VirtualList.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -34,9 +34,8 @@
},

oncreate() {
const { items, _props, itemHeight } = this.get();
const { viewport, container } = this.refs;
const viewportHeight = viewport.offsetHeight;
const { items, _props } = this.get();
const { container } = this.refs;

const keys = Object.keys(this.options.data).filter(key => key !== 'items' && key !== 'component' && key !== 'height' && key !== 'itemHeight');
if (keys.length) {
Expand All @@ -47,45 +46,31 @@
this.set({ _props });
}

this.heightMap = [];
this.rows = container.getElementsByClassName('row');

if (itemHeight) {
this.heightMap = items.map(item => itemHeight);
this.set({
end: Math.min(items.length, Math.ceil(viewportHeight / itemHeight)),
bottom: items.length * itemHeight
});
} else {
this.heightMap = [];

let height = 0;
let i = 0;

while (height < viewportHeight && i < items.length) {
this.set({ end: i + 1 });

const rowHeight = this.heightMap[i] = this.rows[i].offsetHeight;
height += rowHeight;

i += 1;
}

const end = i;
const avg = Math.round(height / i);

for (; i < items.length; i += 1) this.heightMap[i] = avg;

this.set({
bottom: (items.length - end) * avg
});
if (items.length > 0) {
this.initialise();
}

this.on('state', ({ changed, previous, current }) => {
if (changed.items || changed.height || changed.itemHeight) {
if (current.itemHeight && (changed.itemHeight || current.items.length !== this.heightMap.length)) {
if (current.itemHeight && (changed.itemHeight || current.items.length > this.heightMap.length)) {
this.heightMap = current.items.map(() => current.itemHeight);
}

else if (current.items.length > this.heightMap.length) {
if (this.heightMap.length === 0) {
this.initialise();
} else {
let height = 0;
let i = 0;
for (; i < this.heightMap.length; i += 1) height += this.heightMap[i];
const avg = height / this.heightMap.length;
for (; i < current.items.length; i += 1) this.heightMap[i] = avg;
}
}

this.refresh();
}

Expand All @@ -100,6 +85,41 @@
},

methods: {
initialise() {
const { items, itemHeight } = this.get();
const { viewport } = this.refs;
const viewportHeight = viewport.offsetHeight;

if (itemHeight) {
this.heightMap = items.map(item => itemHeight);
this.set({
end: Math.min(items.length, Math.ceil(viewportHeight / itemHeight)),
bottom: items.length * itemHeight
});
} else {
let height = 0;
let i = 0;

while (height < viewportHeight && i < items.length) {
this.set({ end: i + 1 });

const rowHeight = this.heightMap[i] = this.rows[i].offsetHeight;
height += rowHeight;

i += 1;
}

const end = i;
const avg = Math.round(height / i);

for (; i < items.length; i += 1) this.heightMap[i] = avg;

this.set({
bottom: (items.length - end) * avg
});
}
},

refresh() {
const { items, start, end, itemHeight } = this.get();
const { offsetHeight, scrollTop } = this.refs.viewport;
Expand Down
97 changes: 88 additions & 9 deletions test/src/index.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,45 @@ import { assert, test, done } from 'tape-modern';
// setup
const target = document.querySelector('main');

function indent(node, spaces) {
if (node.childNodes.length === 0) return;

if (node.childNodes.length > 1 || node.childNodes[0].nodeType !== 3) {
const first = node.childNodes[0];
const last = node.childNodes[node.childNodes.length - 1];

const head = `\n${spaces} `;
const tail = `\n${spaces}`;

if (first.nodeType === 3) {
first.data = `${head}${first.data}`;
} else {
node.insertBefore(document.createTextNode(head), first);
}

if (last.nodeType === 3) {
last.data = `${last.data}${tail}`;
} else {
node.appendChild(document.createTextNode(tail));
}

let lastType = null;
for (let i = 0; i < node.childNodes.length; i += 1) {
const child = node.childNodes[i];
if (child.nodeType === 1) {
indent(node.childNodes[i], `${spaces} `);

if (lastType === 1) {
node.insertBefore(document.createTextNode(head), child);
i += 1;
}
}

lastType = child.nodeType;
}
}
}

function normalize(html) {
const div = document.createElement('div');
div.innerHTML = html
Expand All @@ -15,6 +54,8 @@ function normalize(html) {
.replace(/>\s+/g, '>')
.replace(/\s+</g, '<');

indent(div, '');

div.normalize();
return div.innerHTML;
}
Expand Down Expand Up @@ -135,22 +176,23 @@ test('props are passed to child component', t => {

test('updates when items change', t => {
const Row = svelte.create(`
<span>{foo}</span>
<div style="height: 80px;">{foo}</div>
`);

const list = new VirtualList({
target,
data: {
items: [{ foo: 'bar'}],
component: Row
component: Row,
height: '100px'
}
});

t.htmlEqual(target.innerHTML, `
<div style='height: 100%;'>
<div style='height: 100px;'>
<div style="padding-top: 0px; padding-bottom: 0px;">
<div class="row">
<span>bar</span>
<div style="height: 80px;">bar</div>
</div>
</div>
</div>
Expand All @@ -161,18 +203,55 @@ test('updates when items change', t => {
});

t.htmlEqual(target.innerHTML, `
<div style='height: 100%;'>
<div style="padding-top: 0px; padding-bottom: 0px;">
<div style='height: 100px;'>
<div style="padding-top: 0px; padding-bottom: 80px;">
<div class="row">
<span>bar</span>
<div style="height: 80px;">bar</div>
</div>

<div class="row">
<span>baz</span>
<div style="height: 80px;">baz</div>
</div>
</div>
</div>
`);

list.destroy();
});

test('updates when items change from an empty list', t => {
const Row = svelte.create(`
<div style="height: 80px;">{foo}</div>
`);

const list = new VirtualList({
target,
data: {
items: [],
component: Row,
height: '100px'
}
});

t.htmlEqual(target.innerHTML, `
<div style='height: 100px;'>
<div style="padding-top: 0px; padding-bottom: 0px;"></div>
</div>
`);

list.set({
items: [{ foo: 'bar'}, { foo: 'baz'}, { foo: 'qux'}]
});

t.htmlEqual(target.innerHTML, `
<div style='height: 100px;'>
<div style="padding-top: 0px; padding-bottom: 80px;">
<div class="row">
<span>qux</span>
<div style="height: 80px;">bar</div>
</div>

<div class="row">
<div style="height: 80px;">baz</div>
</div>
</div>
</div>
Expand Down