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== About the Enhanced Calc Example ==

See [http://www.youtube.com/watch?v=BGmw2IjLLv0&feature=player_embedded Youtube video] for demo of the app.

Source code available from [http://qmlexamples.garage.maemo.org/ qml examples garage page]

== Calculator.qml ==

The file below defines the layouts of the calculator. It uses the button below to draw nice looking button shape, that has glow effect.

<source lang="javascript">
import Qt 4.6

Rectangle {
    width: parent.width; height: 480; color: palette.window
    anchors.fill: parent;
    SystemPalette { id: palette }
    Script { source: "calculator.js" }
</source>

We use the system palette for colors and the calculator.js file for all of the calculation logic.

<source lang="javascript">
    Column {
        x: 2; spacing: 2;
        Row {
          id: numericOperations
          spacing: 2
</source>

We use column layout for the numeric operations (the field that shows the calcuations) layout, with small intendation (2 px) and small padding.

<source lang="javascript">
          Rectangle {
              id: container
              width: 400; height: 55
              border.color: palette.dark; color: palette.base
  
              Text {
                  id: curNum
                  font.bold: true; font.pointSize: 22
                  color: palette.text
                  anchors.right: container.right
                  anchors.rightMargin: 5
                  anchors.verticalCenter: container.verticalCenter
              }
  
              Text {
                  id: currentOperation
                  color: palette.text
                  font.bold: true; font.pointSize: 26
                  anchors.left: container.left
                  anchors.leftMargin: 5
                  anchors.verticalCenter: container.verticalCenter
              }
              
          }
          CalcButton { operation: "Bksp"; id: bksp; opacity: 0 }
        }
</source>

The Text area for the calculations, surrounded by dark border, with two text areas: the operation and the value. The operation (e.g. "*" to signal multiplication, is anchored left, and the calculation is anchored to the right.

<source lang="javascript">
        Item {
            height:460; width: 420;
 
            Item {
                id: basicButtons
                x: 55; width: 460; height: 400
</source>

The above defines the compound item of the basicButtons. The actual buttons are defined below. We intend by default this with 55 so that the buttons in basic layout don't feel like they are in the left side of the screen. This padding is changed in the transition to advanced layout.

<source lang="javascript">
                Row {
                    id: commonOperations
                    spacing: 0
                    height:150
                        
                    CalcButton { 
                        operation: "Advanced"
                        id: advancedCheckBox
                        width: 160
                        toggable: true
                    }
                    CalcButton { operation: "C"; id: c; }
                    CalcButton { operation: "AC"; id: ac;}
                    
                }
</source>

Common operations to clean the calcuations are on one row, along with speacial wider toggle button for advanced mode.

<source lang="javascript">
                Grid {
                    id: numKeypad; y:60; spacing: 0; columns: 3
                    CalcButton { operation: "7" }
                    CalcButton { operation: "8" }
                    CalcButton { operation: "9" }
                    CalcButton { operation: "4" }
                    CalcButton { operation: "5" }
                    CalcButton { operation: "6" }
                    CalcButton { operation: "1" }
                    CalcButton { operation: "2" }
                    CalcButton { operation: "3" }
                    CalcButton { operation: "0" }
                    CalcButton { operation: "." }
                    CalcButton { operation: "=" }                    
                }
</source>

Normal numbers and . and = keys are in grid layout

<source lang="javascript">
                Column {
                    id: simpleOperations
                    x: 240;  y: 60; spacing: 0
                    CalcButton { operation: "x" }
                    CalcButton { operation: "/" }
                    CalcButton { operation: "-" }
                    CalcButton { operation: "+" }
                }
            }
</source>

Basic calculation operations are in one column (for easy layouting).

<source lang="javascript">
            Grid {
                id: advancedButtons
                x: 250; spacing: 0; columns: 2; opacity: 0
                CalcButton { operation: "Abs" }
                CalcButton { operation: "Int" }
                CalcButton { operation: "MC" }
                CalcButton { operation: "Sqrt" }
                CalcButton { operation: "MR" }
                CalcButton { operation: "^2" }
                CalcButton { operation: "MS" }
                CalcButton { operation: "1/x" }
                CalcButton { operation: "M+" }
                CalcButton { operation: "+/-" }
            }
            Row {
              id: trigonometryOperations
              spacing: 0;opacity: 0;y: 280;x:40
              CalcButton { operation: "Sin" }
              CalcButton { operation: "Cos" }
              CalcButton { operation: "Tan" }
              CalcButton { operation: "Log" }
              CalcButton { operation: "e^x" }
              CalcButton { operation: "x^y" }
            }
</source>

Advanced operations are in 2x5 grid and trigonometry operations are on one row. Easy positioning of those compound elements.

<source lang="javascript">
        }
    }

states: State {
        name: "Advanced"; when: advancedCheckBox.toggled == true
        PropertyChanges { target: basicButtons; x: 0 }
        PropertyChanges { target: bksp; opacity: 1 }
        PropertyChanges { target: commonOperations; x: 0;  }
        PropertyChanges { target: advancedButtons; x: 320; opacity: 1 }
        PropertyChanges { target: trigonometryOperations; x:0; y: 300; opacity: 1 }
        
    }
</source>

States definition for advanced mode. Basic mode doesn't need to be defined, as we have defined that already as the default mode of operation. For advanced state, we modify the bacspace to be visible, we move basic buttons a bit, we enable advanced and trigonometry buttons and move them a bit for visual candy.

<source lang="javascript">
    transitions: Transition {
        NumberAnimation { matchProperties: "x,y,width"; easing: "easeOutBounce"; duration: 500 }
        NumberAnimation { matchProperties: "opacity"; easing: "easeInOutQuad"; duration: 500 }
    }
 }
</source>

Above defines the animations for the transition to and from advanced mode.

== CalcButton ==
The code below makes a button that has a glow effect when tapped on.

<source lang="javascript">
import Qt 4.6

Rectangle {
    property alias operation: label.text
    property bool toggable: false
    property bool toggled: false
    signal clicked
    id: button; width: 80; height: 60
    color: "black"      
    BorderImage {
      id: img
      width: parent.width
      height: parent.height
      border.left: 14
      border.right: 14      
      source:"Button_h.png"
      transformOrigin: Item.Center  
      
    }
    
    BorderImage {
      id: bgimg
      width: parent.width
      height: parent.height
      border.left: 14
      border.right: 14      
      source:"Button.png"  
    }
    Text { id: label; anchors.centerIn: parent; color: palette.buttonText }
</source>

On the above, we define the bg of the button and the highlight of the button. The highlight is img and the bg image is, well, bgimg.

<source lang="javascript">
    MouseRegion {
        id: clickRegion
        anchors.fill: parent
        onClicked: {
            doOp(operation);
            button.clicked();
            if (!button.toggable) return;
            button.toggled ? button.toggled = false : button.toggled = true
        }
    }
</source>

Above handles the mouse clicks.

<source lang="javascript">
    states: [
        State {
            name: "Pressed"; when: clickRegion.pressed == true
            PropertyChanges { target: img; scale: 2.0 }
            PropertyChanges { target: button; z: 1 }
            PropertyChanges { target: button.parent; z: 1 }
            PropertyChanges { target: button.parent.parent; z: 1 }
            PropertyChanges { target: img; z: 1.1 }
            PropertyChanges { target: img; opacity: 0 }
            
        }
    ]
</source>

Above defines state "pressed", which triggers the highlight to come up all the way, moves all of the parent objects also up in the stack and sets target opacity for the highlight to be 0.

<source lang="javascript">
        transitions: Transition {
            NumberAnimation { matchProperties: "z,scale"; easing: "easeOutExpo"; duration: 200 }
            NumberAnimation { matchProperties: "opacity"; easing: "easeInQuad"; duration: 300 }
            
        }
}
</source>

Above defines the transitions for the button.

== Calculator.js ==

I won't comment the javascript code. It's self explanatory.

<source lang="javascript">
var curVal = 0;
var memory = 0;
var lastOp = "";
var timer = 0;

function doOp(op) {
    if (disabled(op)) {
        return;
    }

if (op.toString().length==1 && ((op >= "0" && op <= "9") || op==".") ) {
        if (curNum.text.toString().length >= 14)
            return; // No arbitrary length numbers
        if (lastOp.toString().length == 1 && ((lastOp >= "0" && lastOp <= "9") || lastOp==".") ) {
            curNum.text = curNum.text + op.toString();
        } else {
            curNum.text = op;
        }
        lastOp = op;
        return;
    }
    lastOp = op;

// Pending operations
    if (currentOperation.text == "+") {
        curNum.text = Number(curNum.text.valueOf()) + Number(curVal.valueOf());
    } else if (currentOperation.text == "-") {
        curNum.text = Number(curVal) - Number(curNum.text.valueOf());
    } else if (currentOperation.text == "x") {
        curNum.text = Number(curVal) * Number(curNum.text.valueOf());
    } else if (currentOperation.text == "x^y") {
        curNum.text = (Math.pow(Number(curVal),curNum.text.valueOf())).toString();
    } else if (currentOperation.text == "/") {
        curNum.text = Number(Number(curVal) / Number(curNum.text.valueOf())).toString();
    } else if (currentOperation.text == "=") {
    }

if (op == "+" || op == "-" || op == "x" || op=="x^y" || op == "/") {
        currentOperation.text = op;
        curVal = curNum.text.valueOf();
        return;
    }
    curVal = 0;
    currentOperation.text = "";

// Immediate operations
    if (op == "1/x") { // reciprocal
        curNum.text = (1 / curNum.text.valueOf()).toString();
    } else if (op == "^2") { // squared
        curNum.text = (curNum.text.valueOf() * curNum.text.valueOf()).toString();
    } else if (op == "Abs") {
        curNum.text = (Math.abs(curNum.text.valueOf())).toString();
    } else if (op == "Sin") {
        curNum.text = (Math.sin(curNum.text.valueOf())).toString();
    } else if (op == "Cos") {
        curNum.text = (Math.cos(curNum.text.valueOf())).toString();
    } else if (op == "Tan") {
        curNum.text = (Math.tan(curNum.text.valueOf())).toString();
    } else if (op == "Log") {
        curNum.text = (Math.log(curNum.text.valueOf())).toString();
    } else if (op == "e^x") {
        curNum.text = (Math.exp(curNum.text.valueOf())).toString();
    } else if (op == "Int") {
        curNum.text = (Math.floor(curNum.text.valueOf())).toString();
    } else if (op == "+/-") { // plus/minus
        curNum.text = (curNum.text.valueOf() * -1).toString();
    } else if (op == "Sqrt") { // square root
        curNum.text = (Math.sqrt(curNum.text.valueOf())).toString();
    } else if (op == "MC") { // memory clear
        memory = 0;
    } else if (op == "M+") { // memory increment
        memory += curNum.text.valueOf();
    } else if (op == "MR") { // memory recall
        curNum.text = memory.toString();
    } else if (op == "MS") { // memory set
        memory = curNum.text.valueOf();
    } else if (op == "Bksp") {
        curNum.text = curNum.text.toString().slice(0, -1);
    } else if (op == "C") {
        curNum.text = "0";
    } else if (op == "AC") {
        curVal = 0;
        memory = 0;
        lastOp = "";
        curNum.text ="0";
    }
}
</source>

[[Category:Development]]
[[Category:Qt]]

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Editing QML-EnhancedCalcExample

@@ Line 32: / Line 32: @@
 </source>
-We use column layout for the numeric operations (the field that shows the calculations) layout, with small indentation (2 px) and small padding.
+We use column layout for the numeric operations (the field that shows the calcuations) layout, with small intendation (2 px) and small padding.
 <source lang="javascript">
@@ Line 94: / Line 94: @@
 </source>
-Common operations to clean the calculations are on one row, along with special wider toggle button for advanced mode.
+Common operations to clean the calcuations are on one row, along with speacial wider toggle button for advanced mode.
 <source lang="javascript">
@@ Line 174: / Line 174: @@
 </source>
-States definition for advanced mode. Basic mode doesn't need to be defined, as we have defined that already as the default mode of operation. For advanced state, we modify the backspace to be visible, we move basic buttons a bit, we enable advanced and trigonometry buttons and move them a bit for visual candy.
+States definition for advanced mode. Basic mode doesn't need to be defined, as we have defined that already as the default mode of operation. For advanced state, we modify the bacspace to be visible, we move basic buttons a bit, we enable advanced and trigonometry buttons and move them a bit for visual candy.
 <source lang="javascript">
@@ Line 185: / Line 185: @@
 Above defines the animations for the transition to and from advanced mode.
 == CalcButton ==