86 lines
2.9 KiB
QML
86 lines
2.9 KiB
QML
/*
|
|
Copyright (C) 2012 Marco Martin <mart@kde.org>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License along
|
|
with this program; if not, write to the Free Software Foundation, Inc.,
|
|
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
import QtQuick 1.1
|
|
|
|
/**
|
|
* This item can load any qml component, just like a Loader. Important
|
|
* difference, the component will only be loaded when the "when" property is
|
|
* satisfied (ie evaluates to true) in this way it's easy to have big (and
|
|
* memory expensive) parts of the user interface load only when a certain
|
|
* condition is satisfied. For instance the contents of the tabs of a TabBar
|
|
* can be loaded only when they become the current page.
|
|
*/
|
|
Item {
|
|
id: root
|
|
|
|
/**
|
|
* type:bool
|
|
* Condition that tells when to load the declarative component
|
|
*/
|
|
property alias when: loader.when
|
|
|
|
/**
|
|
* type:variant
|
|
* It can be a string with a path name of a qml file or a Component. It's
|
|
* the component that will be loaded when "when" is true. If the component
|
|
* changes the old instantiated component will be deleted and the new one
|
|
* will be loaded instead.
|
|
*/
|
|
property alias source: loader.conditionalSource
|
|
|
|
/**
|
|
* type:Item
|
|
* The item instantiated from component, if any.
|
|
*/
|
|
property alias item: loader.item
|
|
|
|
Loader {
|
|
id: loader
|
|
anchors.fill: parent
|
|
|
|
property bool when: false
|
|
property variant conditionalSource
|
|
|
|
//internal
|
|
property variant oldConditionalSource
|
|
|
|
onWhenChanged: loadTimer.restart()
|
|
onConditionalSourceChanged: loadTimer.restart()
|
|
|
|
Timer {
|
|
id: loadTimer
|
|
interval: 0
|
|
|
|
onTriggered: {
|
|
if (loader.when &&
|
|
(loader.item === null ||
|
|
loader.conditionalSource !== loader.oldConditionalSource)) {
|
|
if (typeof(loader.conditionalSource) === "string") {
|
|
loader.source = loader.conditionalSource
|
|
} else {
|
|
loader.sourceComponent = loader.conditionalSource
|
|
}
|
|
loader.oldConditionalSource = loader.conditionalSource
|
|
loader.item.visible = true
|
|
loader.item.anchors.fill = loader.item.parent
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|