QML-EnhancedCalcExample

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1 About the Enhanced Calc Example
2 Calculator.qml
3 CalcButton
4 Calculator.js

About the Enhanced Calc Example

See Youtube video for demo of the app.

Source code available from 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.

import Qt 4.6
 
 Rectangle {
    width: parent.width; height: 480; color: palette.window
    anchors.fill: parent;
    SystemPalette { id: palette }
    Script { source: "calculator.js" }

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

    Column {
        x: 2; spacing: 2;
        Row {
          id: numericOperations
          spacing: 2

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

          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 }
        }

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.

        Item {
            height:460; width: 420;
 
            Item {
                id: basicButtons
                x: 55; width: 460; height: 400

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.

                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;}
 
                }

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

                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: "=" }                    
                }

Normal numbers and . and = keys are in grid layout

                Column {
                    id: simpleOperations
                    x: 240;  y: 60; spacing: 0
                    CalcButton { operation: "x" }
                    CalcButton { operation: "/" }
                    CalcButton { operation: "-" }
                    CalcButton { operation: "+" }
                }
            }

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

            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" }
            }

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

        }
    }
 
    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 }
 
    }

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.

    transitions: Transition {
        NumberAnimation { matchProperties: "x,y,width"; easing: "easeOutBounce"; duration: 500 }
        NumberAnimation { matchProperties: "opacity"; easing: "easeInOutQuad"; duration: 500 }
    }
 }

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.

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 }

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.

    MouseRegion {
        id: clickRegion
        anchors.fill: parent
        onClicked: {
            doOp(operation);
            button.clicked();
            if (!button.toggable) return;
            button.toggled ? button.toggled = false : button.toggled = true
        }
    }

Above handles the mouse clicks.

    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 }
 
        }
    ]

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.

        transitions: Transition {
            NumberAnimation { matchProperties: "z,scale"; easing: "easeOutExpo"; duration: 200 }
            NumberAnimation { matchProperties: "opacity"; easing: "easeInQuad"; duration: 300 }
 
        }
}

Above defines the transitions for the button.

Calculator.js

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

var curVal = 0;
var memory = 0;
var lastOp = "";
var timer = 0;
 
function disabled(op) {
    if (op == "." && curNum.text.toString().search(/\./) != -1) {
        return true;
    } else if (op == "Sqrt" &&  curNum.text.toString().search(/-/) != -1) {
        return true;
    } else {
        return false;
    }
}
 
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";
    }
}

Retrieved from "http://bugs.maemo.org/QML-EnhancedCalcExample"

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QML-EnhancedCalcExample

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About the Enhanced Calc Example

Calculator.qml

CalcButton

Calculator.js