Complex QML UI questions

2beers

OK. let me know if this works for you. I also started using qml so I'm at a very rookie level , if anyone has a better solution can correct me any time.

you have 3 files: main.qml, Page1.qml, Page2.qml

If I understand correct you want to move from page1 to page2. when you press the rectangle from page1 you will go to page 2 and the same way around. You can also use "transitions":http://doc.qt.nokia.com/4.7/qdeclarativeanimation.html#transitions for a more animated effect

here is the code:

main.qml

@import Qt 4.7

Rectangle {
id:main_rectangle
width: 360
height: 640

Page1{
    id:page1
}

Page2{
    id:page2
}

states: [
    State {
        name: "page2"
        PropertyChanges { target: page1; visible:false; }
        PropertyChanges { target: page2; visible:true; }
    },
    State {
        name: "page1"
        PropertyChanges { target: page2; visible:false; }
        PropertyChanges { target: page1; visible:true; }
    }

]

}
@

Page1.qml

@import Qt 4.7

Rectangle {

width: 360
height: 640

Text {
    id: myText
    x: 93
    y: 152
    width: 80
    height: 20
    text: "page 1"
}

Rectangle {
    id: rectangle1
    x: 93
    y: 216
    width: 100
    height: 100
    color: "#912121"

    MouseArea {
        id: mouse_area1
        anchors.fill: parent
        onClicked: main_rectangle.state="page2"
    }
}

}
@

Page2.qml

@import Qt 4.7

Rectangle {
width: 360
height: 640
visible: false;

Text {
    id: myText
    x: 93
    y: 152
    width: 80
    height: 20
    text: "page 2"
}

Rectangle {
    id: rectangle1
    x: 93
    y: 216
    width: 100
    height: 100
    color: "#912121"

    MouseArea {
        id: mouse_area1
        anchors.fill: parent
        onClicked: main_rectangle.state="page1"
    }
}

}
@

kyleplattner

Thanks so much, I look forward to trying this. This ran fine on your end?

2beers

[quote author="kyleplattner" date="1287845568"]Thanks so much, I look forward to trying this. This ran fine on your end?[/quote]

yes. it runs ok on my side. you load the main.qml file and click the rectangle

kyleplattner

You are very helpful. Let me know if you find any great QML resources for learning.

2beers

Also a better example is to create, destroy the QML objects instead of make them not visible.

@function loadPage1() {
var component = Qt.createComponent("Page1.qml");
if (component.status == Component.Ready) {
var page = component.createObject(main_rectangle);
}
}

@

and on MouseArea you do something like this:

@ onClicked: loadPage1();@

kyleplattner

When I do the later example I return a "ReferenceError: Can't find variable: loadPage1" error. Do I need to make a qmldir file? Will Qt creator auto-generate one for me?

Kyle

2beers

you need to put the mousearea on main.qml and you don't need to create the 2 objects Page1 and Pgae2. you will create after the button is pushed

kyleplattner

In this example, if I wanted to make a button that loaded from a separate QML file as button.qml, why can't I do something like this:

@import Qt 4.7

Rectangle {
property alias text: textItem.text
var page = "page2"

if (page2.visible == true)
{

page = "page1"

}

 width: 100; height: 30
 border.width: 1
 radius: 5
 smooth: true

 gradient: Gradient {
     GradientStop { position: 0.0; color: "lightGray" }
     GradientStop { position: 0.5; color: "gray" }
     GradientStop { position: 1.0; color: "lightGray" }
 }

 Text {
     id: textItem
     anchors.centerIn: parent
     font.pointSize: 20
     color: "white"
     font.family: "Helvetica Neue"
 }

 MouseArea {
     id: mouse_area_button
     anchors.fill: parent
     onClicked: main_rectangle.state = page
 }

}
@

2beers

you example is for button.qml ? or for the main.qml?

kyleplattner

button.qml

2beers

ok so do you receive any error? you defined the page2 in main.qml?

kyleplattner

I am trying to figure out a way for the button to know what page should be navigated to based on what page it is currently on. For instance, if it is on page 1 then it should navigate to page 2 and if it is on page 2 it should navigate to page 1. That is what I was trying to accomplish but it threw me errors.

2beers

ok. but the button where it is build? in main page, page1 or page 2. because if it's build in main page and when you press it you load page1 for example then the button will probably become invisible. if the button is build in page1 or page2 you already know what is the current page. can you post the entire code for every qml page to make a better idea.

kyleplattner

It is loaded in each page file:

main.qml
@import Qt 4.7

Rectangle {
id:main_rectangle
width: 640
height: 480

/* function loadPage1() {
var component = Qt.createComponent("Page1.qml");
if (component.status == Component.Ready) {
var page = component.createObject(main_rectangle);
}
}
*/

Page1{
    id:page1
}

Page2{
    id:page2
}
Page3{
    id:page3
}
Page4{
    id:page4
}
Page5{
    id:page5
}

states: [
    State {
        name: "page5"
        PropertyChanges { target: page1; visible:false; }
        PropertyChanges { target: page2; visible:false; }
        PropertyChanges { target: page5; visible:true; }
        PropertyChanges { target: page4; visible:false; }
        PropertyChanges { target: page3; visible:false; }
    },
    State {
        name: "page4"
        PropertyChanges { target: page1; visible:false; }
        PropertyChanges { target: page2; visible:false; }
        PropertyChanges { target: page5; visible:false; }
        PropertyChanges { target: page4; visible:true; }
        PropertyChanges { target: page3; visible:false; }

    },
    State {
        name: "page3"
        PropertyChanges { target: page1; visible:false; }
        PropertyChanges { target: page2; visible:false; }
        PropertyChanges { target: page5; visible:false; }
        PropertyChanges { target: page4; visible:false; }
        PropertyChanges { target: page3; visible:true; }

    },
    State {
        name: "page2"
        PropertyChanges { target: page5; visible:false; }
        PropertyChanges { target: page4; visible:false; }
        PropertyChanges { target: page3; visible:false; }
        PropertyChanges { target: page1; visible:false; }
        PropertyChanges { target: page2; visible:true; }
    },
    State {
        name: "page1"
        PropertyChanges { target: page5; visible:false; }
        PropertyChanges { target: page4; visible:false; }
        PropertyChanges { target: page3; visible:false; }
        PropertyChanges { target: page2; visible:false; }
        PropertyChanges { target: page1; visible:true; }
    }

]

}
@

page1.qml
@import Qt 4.7

Rectangle {

width: 640
height: 480

Button { text: "Page Two"; x:50; y:232; }
Button { text: "Page Three"; x:200; y:232; }
Button { text: "Page Four"; x:350; y:232; }
Button { text: "Page Five"; x:500; y:232; }

}
@

button.qml
@import Qt 4.7

Rectangle {
property alias text: textItem.text

//var page = "page2"


 width: 100; height: 30
 border.width: 1
 radius: 5
 smooth: true

 gradient: Gradient {
     GradientStop { position: 0.0; color: "lightGray" }
     GradientStop { position: 0.5; color: "gray" }
     GradientStop { position: 1.0; color: "lightGray" }
 }

 Text {
     id: textItem
     anchors.centerIn: parent
     font.pointSize: 20
     color: "white"
     font.family: "Helvetica Neue"
 }

 MouseArea {
     id: mouse_area_button
     anchors.fill: parent
     onClicked: main_rectangle.state = "page2"
 }

}
@

and every subsequent page (page2.qml, page3.qml, etc) is identical to page 1 with minor logical changes.

kyleplattner

I got it to work by placing the mouse_area instructions within each specific page. The next question I have is regarding how I can skin my designs using CSS-like files. Is this possible?

Kyle

kyleplattner

Also, how can I change the state of my button.qml file from my page1.qml?

2beers

you just create states in your button.qml file and then you use buttonName.state=stateName

kyleplattner

So no qmldir file needed? The page1.qml doesn't seem to know that button exists.

2beers

well didn't you created the button in page1.qml ?? did you gave it an id? you need to pass the button id from page1.qml and not from button.qml

2beers

another approach will be to use "Loader":http://doc.qt.nokia.com/4.7/qml-loader.html

Just found out about it. :)