/*******************************************************************************
This file is part of the Shellfish UI toolkit.
Copyright (c) 2020 - 2024 Martin Grimme <martin.grimme@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*******************************************************************************/
"use strict";
shRequire([__dirname + "/object.js", __dirname + "/listmodel.js"], function (obj, listModel)
{
let revisionCounter = 0;
let d = new WeakMap();
/**
* Class representing a repeater.
*
* The repeater is a lightweight element that creates a dynamic set of children
* from its delegate template according to a list model.
*
* The repeater is not a visual element. The children are created within the
* parent container.
*
* Example: Shui code
* ```
* Box {
* Repeater {
* model: ListModel { data: sequence(0, 3) }
* delegate: template Label {
* text: "Label #" + modelData.index
* }
* }
* }
* ```
*
* Usually the repeater creates all of its child elements at once.
* However, by changing the `dynamicItems` property, you can make it create or
* destroy elements dynamically.
*
* Example: Create children dynamically
* ```
* Box {
* overflowBehavior: "scroll"
*
* // reserve space for contents
* Box {
* width: theme.itemWidthLarge
* height: 150 * theme.itemHeightMedium
* }
*
* Repeater {
* model: ListModel { data: sequence(0, 150) }
*
* // create children that are inside the viewport
* dynamicItems: model.data.map((v, idx) => idx).filter(
* idx => (idx + 1) * theme.itemHeightMedium > thisBox.contentY &&
* idx * theme.itemHeightMedium < thisBox.contentY + thisBox.bboxHeight
* )
*
* delegate: template Label {
* position: "free"
* y: modelData.index * theme.itemHeightMedium
* text: "Label #" + modelData.index
* }
* }
* }
* ```
*
* @extends core.Object
* @memberof core
*
* @property {number} count - [readonly] The amount of items.
* @property {fengshui.Template} delegate - (default: `null`) The delegate template. This does not need to be a visual element.
* @property {number[]} dynamicItems - (default: `null`) A list of the index numbers of children to be created dynamically. Children not in this list get destroyed. If `null`, all children get created at once.
* @property {core.Object[]} items - [readonly] The list of items.
* @property {core.ListModel} model - (default: `null`) The list model. You may pass a number value to implicitly create a simple model.
*/
class Repeater extends obj.Object
{
constructor()
{
super();
d.set(this, {
model: null,
delegate: () => null,
dynamicItems: null,
items: [],
recycleBin: []
});
this.notifyable("count");
this.notifyable("dynamicItems");
this.notifyable("model");
this.onInitialization = () =>
{
this.clear();
this.renderAll();
};
this.onDestruction = () =>
{
this.clear();
}
}
get count() { return !! d.get(this).model ? d.get(this).model.size : 0; }
get model() { return d.get(this).model; }
set model(m)
{
const priv = d.get(this);
let mObj = null;
if (typeof m === "number")
{
if (priv.model)
{
while (priv.model.size > m)
{
priv.model.remove(priv.model.size - 1);
}
if (m > priv.model.size)
{
const arr = [];
for (let i = priv.model.size; i < m; ++i) arr.push({ });
priv.model.bulkInsert(priv.model.size, arr);
}
// we're done
return;
}
else
{
mObj = new listModel.ListModel();
const arr = [];
for (let i = 0; i < m; ++i) arr.push({ });
mObj.reset(arr);
}
}
else
{
mObj = m;
}
// clear old content
this.clear();
if (priv.model)
{
// stop watching previous model
priv.model.disconnect("modelReset", this);
priv.model.disconnect("modelInsert", this);
priv.model.disconnect("modelRemove", this);
priv.model.disconnect("modelReplace", this);
priv.model.referenceRemove(this);
}
priv.model = mObj;
if (mObj)
{
mObj.referenceAdd(this);
mObj.connect("modelReset", this, () =>
{
const toDestroy = [];
priv.items.forEach((item, idx) =>
{
toDestroy.push(idx);
});
toDestroy
.sort((a, b) => b < a ? -1 : 1)
.forEach(idx =>
{
this.destroyItem(idx);
});
priv.items = [];
for (let i = 0; i < mObj.size; ++i)
{
priv.items.push(undefined);
}
this.dumpRecycleBin();
this.renderAll();
this.countChanged();
});
mObj.connect("modelInsert", this, (at, size) =>
{
for (let i = 0; i < size; ++i)
{
priv.items = priv.items.slice(0, at)
.concat([undefined])
.concat(priv.items.slice(at));
}
// the index of the following alive items increases
for (let i = at + size; i < priv.items.length; ++i)
{
this.updateItem(i);
}
this.renderAll();
this.countChanged();
});
mObj.connect("modelRemove", this, (at) =>
{
this.destroyItem(at);
// the index of the following items decreases
priv.items.splice(at, 1);
priv.items.forEach((item, idx) =>
{
if (idx >= at)
{
this.updateItem(idx);
}
});
this.renderAll();
this.countChanged();
});
mObj.connect("modelReplace", this, (at) =>
{
this.updateItem(at);
this.renderAll();
});
}
this.renderAll();
this.modelChanged();
this.countChanged();
}
get delegate() { return d.get(this).delegate; }
set delegate(del)
{
d.get(this).delegate = del;
this.renderAll();
}
get dynamicItems() { return d.get(this).dynamicItems; }
set dynamicItems(l)
{
d.get(this).dynamicItems = l.slice().sort((a, b) => Number.parseInt(a) - Number.parseInt(b));
this.dynamicItemsChanged();
this.renderAll();
}
get items() { return d.get(this).items.slice(); }
dumpRecycleBin()
{
const priv = d.get(this);
priv.recycleBin.forEach((item) =>
{
item.referenceRemove(this);
});
priv.recycleBin = [];
}
createItem(idx)
{
const priv = d.get(this);
const modelData = {
revision: revisionCounter,
index: idx,
value: priv.model.at(idx)
};
++revisionCounter;
let item = null;
if (priv.recycleBin.length > 0)
{
item = priv.recycleBin.pop();
item.modelData = modelData;
}
else
{
item = priv.delegate({ modelData: modelData });
if (item)
{
item.referenceAdd(this);
}
}
//console.log("createItem " + idx);
return item;
}
updateItem(idx)
{
const priv = d.get(this);
const modelData = {
revision: revisionCounter,
index: idx,
value: priv.model.at(idx)
};
++revisionCounter;
if (modelData.value !== undefined)
{
const item = this.getItem(idx);
if (item)
{
item.modelData = modelData;
}
}
}
destroyItem(idx)
{
const priv = d.get(this);
const item = this.getItem(idx);
if (item)
{
//console.log("destroyItem " + idx);
//priv.recycleBin.push(item);
item.parent = null;
item.referenceRemove(this);
}
}
getItem(idx)
{
return d.get(this).items[idx];
}
clear()
{
d.get(this).items.forEach(item =>
{
if (item !== undefined)
{
item.parent = null;
item.referenceRemove(this);
}
});
d.get(this).items = [];
}
renderAll()
{
this.defer(() => { this.doRenderAll(); }, "renderAll");
}
doRenderAll()
{
if (this.lifeCycleStatus !== "initialized")
{
return;
}
const model = d.get(this).model;
const delegate = d.get(this).delegate;
const items = d.get(this).items;
if (! model || ! delegate || ! this.parent)
{
return;
}
//console.log("render " + this.objectLocation);
const f = () =>
{
const existingItems = items.filter(c => c !== undefined);
const createDynamically = d.get(this).dynamicItems !== null;
const dynamicItems = createDynamically ? d.get(this).dynamicItems.slice()
: null;
for (let i = 0; i < model.size; ++i)
{
while (createDynamically && dynamicItems.length > 0 && dynamicItems[0] < i)
{
dynamicItems.shift();
}
const mayCreate = ! createDynamically || dynamicItems.length > 0 && dynamicItems[0] === i;
//const isAlive = d.get(this).dynamicItems !== null ? d.get(this).dynamicItems.indexOf(i) !== -1
// : true;
if (items[i] === undefined)
{
if (mayCreate)
{
const item = this.createItem(i);
if (item)
{
if (existingItems.length === 0)
{
this.parent.add(item);
}
else
{
this.parent.add(item, existingItems[0]);
}
items[i] = item;
}
}
}
else
{
if (existingItems.length > 0 && existingItems[0] === items[i])
{
existingItems.shift();
}
if (! mayCreate && items[i])
{
this.destroyItem(i);
items[i] = undefined;
}
}
}
};
//const now = Date.now();
if (this.parent.withoutSizing)
{
this.parent.withoutSizing(f);
}
else
{
f();
}
//console.log("Filling repeater took " + (Date.now() - now) + " ms");
}
}
exports.Repeater = Repeater;
});