plasma-framework/declarativeimports/plasmacomponents/qml/ScrollBar.qml
Aleix Pol f3e607c2cf Improve response and behavior in ScrollBar
When contentHeight and contentY change at the same time, we got to
some weird states where the scrollbar would trigger a change in the
Flickable positioning that wasn't triggered by the user, this should
be fixed now.

Also don't use the handle position to move the Flickable scrolling
if the scrollbar is disabled or non-interactive. It shouldn't be needed
now but it helps keeping the complexity to a minimum.

REVIEW: 105808
2012-08-01 13:36:22 +02:00

232 lines
7.9 KiB
QML

/*
* Copyright (C) 2011 by Daker Fernandes Pinheiro <dakerfp@gmail.com>
* Copyright (C) 2011 Marco Martin <mart@kde.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2, 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 Library 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.
*/
/**Documented API
Inherits:
Item
Imports:
org.kde.plasma.core
QtQuick 1.1
Description:
Just a simple Scroll Bar which is using the plasma theme.
This component does not belong to the QtComponents API specification
but it was base on ScrollDecorator component.
You should not use it for touch interfaces, use a flickable and a
ScrollDecorator instead.
By default, this component will look and behave like a scroll decorator
on touchscreens
Properties:
enumeration orientation:
This property holds the orientation where the ScrollBar will scroll.
The orientation can be either Qt.Horizontal or Qt.Vertical
The default value is Qt.Vertical.
bool inverted:
This property holds if the ScrollBar will increase the Flickable
content in the normal direction (Left to Right or Top to Bottom) or
if this will be inverted.
The default value is false.
bool updateValueWhileDragging:
This property holds if the Scrollbar will update the Flickeble
position while dragging or only when released.
The default value is true.
real stepSize:
This property holds how many steps exists while moving the handler.
If you want the ScrollBar buttons to appear you must set this property
with a value bigger than 0.
The default value is 0.
bool pressed:
This property holds if the ScrollBar is pressed.
real scrollButtonInterval:
This property holds the interval time used by the ScrollBar button
to increase or decrease steps.
Flickable flickableItem:
This property holds the Flickable component which the ScrollBar will
interact with.
bool interactive:
This property holds if the ScrollBar is interactive.
The default value is true.
bool enabeld:
This property holds if the button will be enabled for user
interaction.
The default value is true.
**/
import QtQuick 1.1
import org.kde.plasma.core 0.1 as PlasmaCore
import "private" as Private
/**
* A generic ScrollBar/ScrollDecorator component:
* Always prefer this to ScrollDecorator that is not available on desktop.
* By default, this component will look and behave like a scroll decorator on touchscreens
*/
// TODO: add support mouse wheel events
Item {
id: scrollbar
// Common API
property Flickable flickableItem: null
property int orientation: Qt.Vertical
property bool interactive: true
// Plasma API
property bool inverted: false
property alias stepSize: range.stepSize
property bool pressed: internalLoader.item.mouseArea?internalLoader.item.mouseArea.pressed:false
property real scrollButtonInterval: 50
implicitWidth: internalLoader.isVertical ? (interactive ? 16 : 12) : 200
implicitHeight: internalLoader.isVertical ? 200 : (interactive ? 16 : 12)
// TODO: needs to define if there will be specific graphics for
// disabled scroll bars
opacity: enabled ? 1.0 : 0.5
visible: flickableItem && internalLoader.handleEnabled
anchors {
right: flickableItem.right
left: (orientation == Qt.Vertical) ? undefined : flickableItem.left
top: (orientation == Qt.Vertical) ? flickableItem.top : undefined
bottom: flickableItem.bottom
}
Loader {
id: internalLoader
anchors.fill: parent
//property bool handleEnabled: internalLoader.isVertical ? item.handle.height < item.contents.height : item.handle.width < item.contents.width
property bool handleEnabled: internalLoader.isVertical ? flickableItem.contentHeight > flickableItem.height : flickableItem.contentWidth > flickableItem.width
property bool isVertical: orientation == Qt.Vertical
function incrementValue(increment)
{
if (!flickableItem)
return;
if (internalLoader.isVertical) {
flickableItem.contentY = Math.max(0, Math.min(flickableItem.contentHeight - flickableItem.height,
flickableItem.contentY + increment))
} else {
flickableItem.contentX = Math.max(0, Math.min(flickableItem.contentWidth - flickableItem.width,
flickableItem.contentX + increment))
}
}
Connections {
target: flickableItem
onContentHeightChanged: {
range.value = flickableItem.contentY
}
onContentYChanged: {
if (internalLoader.isVertical) {
range.value = flickableItem.contentY
}
}
onContentXChanged: {
if (!internalLoader.isVertical) {
range.value = flickableItem.contentX
}
}
}
Connections {
target: internalLoader.item.handle
onYChanged: updateFromHandleTimer.running = true
onXChanged: updateFromHandleTimer.running = true
}
RangeModel {
id: range
minimumValue: 0
maximumValue: {
var diff;
if (internalLoader.isVertical) {
diff = flickableItem.contentHeight - flickableItem.height
} else {
diff = flickableItem.contentWidth - flickableItem.width
}
return Math.max(0, diff)
}
stepSize: 10
inverted: scrollbar.inverted
positionAtMinimum: 0
positionAtMaximum: {
if (internalLoader.isVertical) {
internalLoader.item.contents.height - internalLoader.item.handle.height
} else {
internalLoader.item.contents.width - internalLoader.item.handle.width
}
}
onValueChanged: {
if (flickableItem.moving) {
return
}
if (internalLoader.isVertical) {
flickableItem.contentY = value
} else {
flickableItem.contentX = value
}
}
onPositionChanged: {
if (internalLoader.item.mouseArea && internalLoader.item.mouseArea.pressed) {
return
}
if (internalLoader.isVertical) {
internalLoader.item.handle.y = position
} else {
internalLoader.item.handle.x = position
}
}
}
Timer {
id: updateFromHandleTimer
interval: 10
onTriggered: {
if (internalLoader.isVertical && enabled && interactive) {
range.position = internalLoader.item.handle.y
} else {
range.position = internalLoader.item.handle.x
}
}
}
source: interactive ? "private/ScrollBarDelegate.qml" : "private/ScrollDecoratorDelegate.qml"
}
}