QML-EnhancedCalcExample
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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.
<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 calculations) layout, with small indentation (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 calculations are on one row, along with special 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 backspace 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 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";
}
} </source>
