CircleMeter: begin a better design

Design proposed by David.

qml/CircleMeter.qml

@@ -8,14 +8,22 @@ Item {
 	/// current level
 	property double level: 0.5 
 	/// minimum level
-	property double min: -1
+	property double min: -50
 	/// maximum level
-	property double max: 1
+	property double max: 50
 	/// numbers to write on the scale
-	property variant marks: [-1, -0.5, 0, 0.5, 1, -0.2, 0.2, -0.8, 0.8]
+	property variant marks: [-40, -20, 0, 20, 40]
+	/// marks regions colors
+	property variant region_color: ["red", "yellow", "green", "yellow", "red"]
 	/// theme object
 	property QtObject theme
 
+	property double r_circle_min: 0.85
+	property double r_circle_max: 1
+
+	property double amin: angle(min)
+	property double amax: angle(max)
+
 	/// positions helper functions
 	function angle(level) {
 		return (level - min) / (max - min) * Math.PI - Math.PI / 2
@@ -28,38 +36,78 @@ Item {
 		return height - height * k * Math.cos(angle)
 	}
 
+	/// objects draw
+
+	function arc(ctx, k) {
+		ctx.beginPath()
+		ctx.moveTo(getx(amin, k), gety(amin, k))
+		for (var i = amin + 0.01; i <= amax; i+=0.01) {
+			ctx.lineTo(getx(i,k), gety(i,k))
+		}
+		ctx.stroke()
+	}
+
+	function arc_part(ctx, k, a1, a2) {
+		ctx.lineTo(getx(a1,k), gety(a1,k))
+		var eps = 0.01
+		if (a2 > a1) {
+			for (var i = a1 + eps; i < a2; i+=eps) {
+				ctx.lineTo(getx(i,k), gety(i,k))
+			}
+		}
+		else {
+			for (var i = a1 - eps; i > a2; i-=eps) {
+				ctx.lineTo(getx(i,k), gety(i,k))
+			}
+		}
+		ctx.lineTo(getx(a2,k), gety(a2,k))
+	}
+
+	function line_mark(ctx, value, r_min, r_max) {
+		var a = angle(value)
+		ctx.beginPath()
+		ctx.moveTo(getx(a, r_min), gety(a, r_min))
+		ctx.lineTo(getx(a, r_max), gety(a, r_max))
+		ctx.stroke()
+	}
+
 	/// Ellipse
 	Canvas {
 		id: ellipse
 		anchors.fill: parent
 
-		property double mark_k_min: 0.90
+		property double r_text: 0.92
-		property double mark_k_max: 0.95
+
-		property double mark_k_text: 0.85
+		property double l_marker: 0.035
-		property int font_size: 16
+		property double h_marker: 7
+		property int font_size: 20
 
 		onPaint: {
 			var ctx = getContext('2d');
 			ctx.strokeStyle = theme.primaryColor
 			ctx.lineWidth = 1
-			ctx.beginPath()
+
-			ctx.moveTo(0,height - 1)
+			arc(ctx, r_circle_min)
-			ctx.bezierCurveTo(0, -height * 0.33, width - 1, -height * 0.33, width - 1, height - 1)
+			arc(ctx, r_circle_max)
-			//ctx.closePath()
+
-			ctx.stroke()
-			console.log("ellipse done")
 			ctx.font = font_size + "px sans-serif"
 			ctx.textAlign = "center"
 
+			ctx.lineWidth = h_marker
+			ctx.strokeStyle = theme.secondaryColor
 			for (var i = 0; i < marks.length; i++) {
+				line_mark(ctx, marks[i], r_circle_min - l_marker, r_circle_min + l_marker)
 				var a = angle(marks[i])
-				ctx.beginPath()
+				ctx.fillText(marks[i], getx(a, r_text), gety(a, r_text) + 4)
-				ctx.moveTo(getx(a, mark_k_min), gety(a, mark_k_min))
-				ctx.lineTo(getx(a, mark_k_max), gety(a, mark_k_max))
-				ctx.stroke()
-				ctx.fillText(marks[i], getx(a, mark_k_text), gety(a, mark_k_text))
 				ctx.strokeText()
 			}
+
+			// "beetween" marks
+			ctx.lineWidth = 1
+			ctx.strokeStyle = theme.primaryColor
+			for (var i = 0; i < marks.length - 1; i++) {
+				line_mark(ctx, (marks[i] + marks[i+1])/2, r_circle_min, r_circle_max)
+			}
 		}
 	}
 
@@ -67,20 +115,71 @@ Item {
 		/// level arrow
 		id: arrow
 		anchors.fill: parent
-		property double k: 0.99
+		property double k: 0.82
 		property double k_base: 0.1
 		property double angle: parent.angle(level)
 
 		onPaint: {
 			var ctx = getContext('2d');
+			ctx.clearRect(0,0,width,height)
 			ctx.strokeStyle = theme.primaryColor
 			ctx.lineWidth = 1
 			ctx.beginPath()
 			ctx.moveTo(getx(angle, k_base), gety(angle, k_base))
 			ctx.lineTo(getx(angle, k), gety(angle, k))
 			ctx.stroke()
-
-			console.log("angle: " + angle)
 		}
 	}
+
+	Canvas {
+		/// region colors
+		id: regions
+		anchors.fill: parent
+		z: -4
+		onPaint: {
+			var ctx = getContext('2d');
+			ctx.clearRect(0,0,width,height)
+
+			var l1 = min
+			var l2
+
+			for (var i = 0; i < marks.length; i++) {
+				if (i == marks.length - 1) l2 = max
+				else l2 = (marks[i] + marks[i+1]) / 2
+
+				if (level <= l2) {
+					var a1 = angle(l1)
+					var a2 = angle(l2)
+					ctx.fillStyle = region_color[i]
+					ctx.beginPath()
+					ctx.moveTo(getx(a1, r_circle_min), gety(a1, r_circle_min))
+					arc_part(ctx, r_circle_min, a1, a2)
+					arc_part(ctx, r_circle_max, a2, a1)
+					ctx.lineTo(getx(a1, r_circle_min), gety(a1, r_circle_min))
+					ctx.fill()
+					break;
+				}
+				l1 = l2
+			}
+		}
+	}
+
+	Behavior on level {
+		NumberAnimation {
+			duration: 50
+			easing.amplitude: max - min
+		}
+	}
+
+	onLevelChanged: {
+		arrow.requestPaint()
+		regions.requestPaint()
+	}
+
+	MouseArea {
+		anchors.fill: parent
+		onClicked: {
+			level = Math.random() * (max - min) + min
+		}
+	}	
 }

qml/DesktopTheme.qml

@@ -2,7 +2,7 @@ import QtQuick 2.0
 
 Item {
 	property color primaryColor: "#000000"
-	property color secondaryColor: "#444444"
+	property color secondaryColor: "#777777"
 	property int paddingSmall: 4
 	property int paddingLarge: 20
 	property int fontSizeSmall: 10

qml/Scene.qml

@@ -7,7 +7,7 @@ import QtQuick 2.0
 
 Item {
 	width: 600
-	height: 400
+	height: 300
 
 	DesktopTheme {
 		id: theme