2016-03-31 15:12 GMT+02:00 Kristoffersen, Even (NO14)
<even.kristoffer...@honeywell.com>:
> I think Connections is what you are looking for:
>
> Connections
> {
> id: editingConnections
> target: null
>
> onRightPressed: ...
> ...
> ...
> }
>
> Connections
> {
> id: navigationConnections
> target: Keys
There seems to be a problem with this approach, as Keys isn't defined
at this point. I get:
Unable to assign undefined to QObject*
I guess Keys hasn't been attached yet.
>
> onRightPressed: ...
> ...
> ...
> }
>
> ..
>
> states: [
> State {
> name: "editing"
> PropertyChanges {
> target: editingConnections
> target: Keys //Don't know if this works
> since the parameter is called target as well. If it doesn't work you'll have
> to do something like this in editingConnections declaration:
> //target: meters.state === "editing" ? Keys :
> null
> }
> PropertyChanges {
> target: navigationConnections
> target: null
> }
> }
> ]
>
>
> -----Original Message-----
> From: Interest
> [mailto:interest-bounces+even.kristoffersen=honeywell....@qt-project.org] On
> Behalf Of Elvis Stansvik
> Sent: 31. mars 2016 14:38
> To: interest@qt-project.org Interest <interest@qt-project.org>
> Subject: [Interest] Declaratively handle key presses / navigation differently
> depending on state (QML)
>
> Hi,
>
> I'm working on an item representing a number to be edited by the user.
>
> My input is quite limited (only Left, Right and Enter, where Left and Right
> is actually the turning of a wheel), so the idea is to let the user
> navigating to the item with Left/Right, which will give it focus.
> If the user then presses Enter, the item enters and "editing" state.
> In the "editing" state, Left and Right will increase/descreas the number, and
> pressing Enter again will exit the "editing" state, returning to the default
> state ("").
>
> How can I handle key presses differently depending on state without resorting
> to procedural code like if/else on the state inside the onXXXPressed
> handlers? I thought I'd be able to assign to Keys.onXXXPressed inside State {
> PropertyChanges { ... }, but the property is not recognized there (I'm
> guessing because it's an attached property..?).
>
> Also, the KeyNavigation.left/right/etc. is a convenient way to do the
> navigation between items, but it seems incompatible with the
> Keys.onXXXPressed handlers? I thought I'd be able to skip accepting the key
> even in a Keys.onXXXPressed handler, and have it pass through to the
> KeyNavigation.xxx handler...? (I can do the navigation with
> someItem.forceActiveFocus() instead, but it's more typing and more error
> prone).
>
>
> Below is a working but rather ugly example of two numbers that can be edited
> this way. One can navigate between the numbers with Left/Right, and toggle
> "editing" mode with Enter (in which Left and Right controls the number value
> instead).
>
> How can I make this example more declarative / less ugly? (Besides the
> obviously putting things in a reusable component).
>
> Example:
>
> import QtQuick 2.4
> import QtQuick.Window 2.2
>
> Window {
> width: 800
> height: 600
> visible: true
>
> Row {
> spacing: 30
> Column {
> Text {
> text: "Meters"
> }
> Text {
> id: meters
> text: value
> font.underline: activeFocus
> font.pixelSize: 100
>
> property int value: 3
>
> focus: true
>
> states: [
> State {
> name: "editing"
> PropertyChanges {
> target: meters
> color: "green"
> }
> }
> ]
>
> Keys.onReturnPressed: {
> if (state == "")
> state = "editing"
> else
> state = ""
> event.accepted = true
> }
>
> Keys.onRightPressed: {
> if (state == "editing")
> value++
> else
> centimeters.forceActiveFocus()
> event.accepted = true
> }
>
> Keys.onLeftPressed: {
> if (state == "editing")
> value--
> else
> centimeters.forceActiveFocus()
> event.accepted = true
> }
> }
> }
> Column {
> Text {
> text: "Centimeters"
> }
> Text {
> id: centimeters
> text: value
> font.underline: activeFocus
> font.pixelSize: 100
>
> property int value: 14
>
> states: [
> State {
> name: "editing"
> PropertyChanges {
> target: centimeters
> color: "green"
> }
> }
> ]
>
> Keys.onReturnPressed: {
> if (state == "")
> state = "editing"
> else
> state = ""
> event.accepted = true
> }
>
> Keys.onRightPressed: {
> if (state == "editing")
> value++
> else
> meters.forceActiveFocus()
> event.accepted = true
> }
>
> Keys.onLeftPressed: {
> if (state == "editing")
> value--
> else
> meters.forceActiveFocus()
> event.accepted = true
> }
> }
> }
> }
> }
>
>
> Thanks for any advice,
> Elvis
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