[Qt-qml] Access to element property

Tue Mar 1 01:37:41 CET 2011

Hi Thomas,

Do you know which row(s) of the ListView you will be targeting? Will it for example, always be the currentItem/currentIndex? Or do you need to call save for all of the rows in the ListView? (Or does the ListView only ever instantiate one rowComponent?)

Regards,
Michael

On 28/02/2011, at 8:38 PM, ext Thomas PABST wrote:

Element ids are only accessible within the component where they are declared (in the example below, element1 would only be accessible within rowComponent). One of the reasons for this is that a component can be instantiated many times -- for example a ListView will instantiate its delegate once for every row -- and we don't want to end up with many elements sharing the same 'global' id.

Here are a couple ideas of some things you could try (depending on how the program is structured):

* putting the save() function within topRow
* adding properties to topRow (which become the "public API" of any items instantiated by rowComponent (you'll still need a way to address the right element in the list, though))
* passing the text as a parameter to save() (if the button lives within the delegate)

Regards,
Michael

Hi,

Some interesting ideas.

* putting the save() function within topRow

Interesting idea, but in this case how can I send a signal to this function ? Because that's the main problem. The first signal, when we push a button, comes from another part of the program. This button isn't within the component.

* adding properties to topRow (which become the "public API" of any items instantiated by rowComponent (you'll still need a way to address the right element in the list, though))
* passing the text as a parameter to save() (if the button lives within the delegate)

Still the same thing ! How could I access to the API ?

Well, the purpose is the get a value from an element which inside a component, or send a signal to this component to ask a function to do the job.

Regards
Thomas

-----------------------------------------------------
Thomas PABST
thomas.pabst at gmail.com<mailto:thomas.pabst at gmail.com>

2011/2/28 <michael.brasser at nokia.com<mailto:michael.brasser at nokia.com>>
Hi Thomas,

Element ids are only accessible within the component where they are declared (in the example below, element1 would only be accessible within rowComponent). One of the reasons for this is that a component can be instantiated many times -- for example a ListView will instantiate its delegate once for every row -- and we don't want to end up with many elements sharing the same 'global' id.

Here are a couple ideas of some things you could try (depending on how the program is structured):

* putting the save() function within topRow
* adding properties to topRow (which become the "public API" of any items instantiated by rowComponent (you'll still need a way to address the right element in the list, though))
* passing the text as a parameter to save() (if the button lives within the delegate)

Regards,
Michael

On 26/02/2011, at 1:24 AM, ext Thomas PABST wrote:

Hi,

In fact, the ListView is use in first place to show  informations details from a contactList. I want add a new contact to the model. The RowElement contain an QML TextEdit Element which load a virtual keyboard. This virtual keyboard insert values on Each TextEdit. So the goal is to save new values when user click a button. That's the purpose of the function saveContact(). I don't want save the value in first place, but after, only if the user click on the save button. That's why I want to get the value.

-----------------------------------------------------
Thomas PABST
thomas.pabst at gmail.com<mailto:thomas.pabst at gmail.com>

2011/2/25 Tobias Renz <Tobias.Renz at jdsu.com<mailto:Tobias.Renz at jdsu.com>>

Hi,

If your code example below is right I think you might be wrong on how to use the list view.

Typically you would set your values in the data model

ListModel {
    id: data

    ListElement {
          value: "value1"
    }
    ListElement {
          value: "value2"
    }
    ListElement {
          value: "value3"
    }
 }

Setting it to the listView would be the same as you did:

   ListView {
       id: listView
       ...
       model: data

       delegate: rowComponent

   } // End of ListView id: listView

But then the delegate would only be one element of the list. The list itself would generate the elements in the "column".

   Component {
       id: rowComponent

       Text {
           id: element
           value: model.value
               text: model.value
       }

=> The ListView will now show three Text-Elements below each other in a List or "Column". Showing the value. The key is that you bind the value from the model to the element in the list.
  Then the value is already stored in the model which you call data. If you want to change the value you would directly change it in the model then the value in the list aka in the delegate will also change.

But I'm not sure if this is the intended use of your program or if you want to do something special with ListView?

Regards,
Tobias

Date: Fri, 25 Feb 2011 13:04:06 +0100
From: Thomas PABST <thomas.pabst at gmail.com<mailto:thomas.pabst at gmail.com>>
Subject: [Qt-qml] Access to element property
To: "qt-qml.qt.nokia.com<http://qt-qml.qt.nokia.com/>" <Qt-qml at qt.nokia.com<mailto:Qt-qml at qt.nokia.com>>
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       <AANLkTinRX7EC1y5b8WubamG0obBvCXkZj8MDVy5f6yCz at mail.gmail.com<mailto:AANLkTinRX7EC1y5b8WubamG0obBvCXkZj8MDVy5f6yCz at mail.gmail.com>>
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Hi,

I'm currently trying to get value from an QML element which is the delegate of a ListView, but the variable cannot be found.
With the function saveData() I would like to get the value from RowElement where the id is element1. But qmlViewer return a ReferenceError: Can't find
variable: element1.
Is there a way to get it ?

The following example implement only properties necessary to understand the problem.

thanks

Item {
   id: main

   property variant data

   function saveData()
   {
       data.value = element1.value;
       ...
   }

   ListView {
       id: listView
       ...
       model: data

       delegate: rowComponent

   } // End of ListView id: listView

   Component {
       id: rowComponent

       Column {
           id: topRow

           RowElement {
               id: element1
               value: "value1"
           }

           RowElement {
               id: element2
               value: "value2"
           }

           RowElement {
               id: element3
               value: "value3"
           }
       }// End of Column id: topRow
   } // End of Component id: rowComponent }

-----------------------------------------------------
Thomas PABST
thomas.pabst at gmail.com<mailto:thomas.pabst at gmail.com>
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