2016-06-09 7:54 GMT+02:00 Elvis Stansvik <elvst...@gmail.com>:
> 2016-06-08 23:59 GMT+02:00 Jason H <jh...@gmx.com>:
>> I'm coming into this late, but can't you just set up:
>>
>> Item { // delegate
>>
>> Item {
>> id: view1
>> visible: some_data_item_property == true
>> }
>> Item {
>> id: view2
>> visible: !view1.visible
>> }
>> }
>>
>> Then make view1 and view2 your different delegates? You're just going after
>> two diferent views, right?
>
> Well it's ~5, but indeed that seems to work great! A little test:
>
>
> import QtQuick 2.4
> import QtQuick.Window 2.2
>
> import "."
>
> Window {
> title: "Test"
> width: 600
> height: 900
> visible: true
>
> ListModel {
> id: listModel
> dynamicRoles: true
> Component.onCompleted: {
> append({
> "type": "color",
> "name": "foo",
> "value": "red"
> });
> append({
> "type": "flag",
> "name": "bar",
> "value": false
> });
> append({
> "type": "choice",
> "name": "bar",
> "value": "Foo",
> "choices": ["Foo", "Bar"]
> });
> }
> }
>
> ListView {
> anchors.fill: parent
>
> model: listModel
> delegate: Rectangle {
> implicitHeight: {
> if (type === "color")
> return colorDelegate.implicitHeight
> if (type === "flag")
> return flagDelegate.implicitHeight
> if (type === "choice")
> return choiceDelegate.implicitHeight
> }
> Text {
> id: colorDelegate
> text: value + " (color)"
> visible: type === "color"
> }
> Text {
> id: flagDelegate
> text: value + " (flag)"
> visible: type === "flag"
> }
> Text {
> id: choiceDelegate
> text: value + " (choice)"
> visible: type === "choice"
> }
> }
> }
> }
>
It does not really solve the "problem" though. Say one of my delegates
is a ColorDelegate for when the item represents a color, and I want to
provide editing (my model has a setColor(index, color)).
I will then have to use parent.ListView.view.model.setColor(index,
color), thereby tying the color delegate to this way of working: It
can't be reused in another context where I have a model known to
consist of only colors (well not without artificially nesting it
inside something else, like an invisible Rectangle, so that the
reference to setColor works).
On the C++ side, it's a bit easier to make delegates that are reusable
in these two situations, since you work with createEditor and friends
instead.
Elvis
>
> I wonder why I haven't seen this approach before while searching around.
>
> Elvis
>
>>
>> Sent: Wednesday, June 08, 2016 at 11:49 AM
>> From: "Elvis Stansvik" <elvst...@gmail.com>
>> To: "Kristoffersen, Even (NO14)" <even.kristoffer...@honeywell.com>,
>> "interest@qt-project.org Interest" <interest@qt-project.org>
>>
>> Subject: Re: [Interest] Awkwardness of delegates in heterogenous ListViews
>>
>> 2016-06-08 15:41 GMT+02:00 Kristoffersen, Even (NO14)
>> <even.kristoffer...@honeywell.com>:
>>> Have you tried something like this in the delegate?
>>>
>>> property alias some_descriptive_name: parent
>>
>> It seems it's not allowed to use parent as the target of an alias (?):
>>
>> file:///home/estan/qte/qte/qml/ItemDelegate.qml:5 Invalid alias reference.
>> Unable to find id "parent"
>>
>> And this would still tie my "subdelegates" to this structure. They could not
>> be reused in other places, where lists are homogenous and I'm not using the
>> Loader approach.
>>
>> But I guess there's really no way to make a delegate that can be used in
>> both the "normal" situation and in the indirect-through-Loader approach.
>>
>> Elvis
>>
>>>
>>> (Not tested, just an idea)
>>>
>>> -Even
>>>
>>> -----Original Message-----
>>> From: Interest
>>> [mailto:interest-bounces+even.kristoffersen=honeywell....@qt-project.org] On
>>> Behalf Of Elvis Stansvik
>>> Sent: 8. juni 2016 15:34
>>> To: interest@qt-project.org Interest <interest@qt-project.org>
>>> Subject: Re: [Interest] Awkwardness of delegates in heterogenous ListViews
>>>
>>> 2016-06-08 15:32 GMT+02:00 Elvis Stansvik <elvst...@gmail.com>:
>>>> Hi all,
>>>>
>>>> I'm currently using a "type" role in my items and then a Loader as
>>>> delegate, to give a level of indirection and let me choose the actual
>>>> delegate based on the "type" of the item.
>>>>
>>>> This explains it better (from my ListView):
>>>>
>>>> delegate: Loader {
>>>> sourceComponent: {
>>>> switch (type) {
>>>> case "color":
>>>> return colorDelegate
>>>> case "flag":
>>>> return flagDelegate
>>>> ...
>>>> }
>>>> }
>>>>
>>>> Component {
>>>> id: colorDelegate
>>>>
>>>> ColorDelegate { }
>>>> }
>>>>
>>>> Component {
>>>> id: flagDelegate
>>>>
>>>> FlagDelegate { }
>>>> }
>>>>
>>>> ...
>>>> }
>>>>
>>>> What I don't like with this approach is that inside my delegates, e.g.
>>>> ColorDelegate.qml, I have to use parent.ListView.view.model to get a
>>>
>>> I should clarify: I have to use this notation since it is the parent (the
>>> Loader) which is the real delegate and has the ListView attached properties.
>>>
>>> Elvis
>>>
>>>> reference to the model (needed for editing operations). The use of
>>>> "parent" here assumes a certain layout, but I see no other way :(
>>>>
>>>> How have others solved the issue of delegates for heterogenous lists?
>>>>
>>>> Best regards,
>>>> Elvis
>>> _______________________________________________
>>> Interest mailing list
>>> Interest@qt-project.org
>>> http://lists.qt-project.org/mailman/listinfo/interest
>>
>> _______________________________________________ Interest mailing list
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>> http://lists.qt-project.org/mailman/listinfo/interest
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