2 * Copyright © 2019 Damyan Ivanov.
3 * This file is part of MoLe.
4 * MoLe is free software: you can distribute it and/or modify it
5 * under the term of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your opinion), any later version.
9 * MoLe is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License terms for details.
14 * You should have received a copy of the GNU General Public License
15 * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
18 package net.ktnx.mobileledger.ui;
20 import android.content.Context;
21 import android.graphics.Canvas;
22 import android.graphics.Paint;
23 import android.graphics.Path;
24 import android.graphics.RectF;
25 import android.graphics.Shader;
26 import android.graphics.SweepGradient;
27 import android.util.AttributeSet;
28 import android.util.Log;
29 import android.view.MotionEvent;
30 import android.view.View;
32 import net.ktnx.mobileledger.utils.Colors;
33 import net.ktnx.mobileledger.utils.DimensionUtils;
35 import androidx.annotation.Nullable;
37 public class HueRing extends View {
38 private static final int hueStepDegrees = 15;
39 private Paint ringPaint, initialPaint, currentPaint, markerPaint;
40 private int centerX, centerY;
43 private int initialHueDegrees;
44 private int color, hueDegrees;
47 private float bandWidth;
49 private float innerDiameter;
50 private float centerR;
51 private RectF centerRect;
52 private RectF ringRect;
53 private int markerOverflow;
54 private int markerStrokeWidth;
55 public HueRing(Context context, @Nullable AttributeSet attrs) {
56 super(context, attrs);
57 init(Colors.DEFAULT_HUE_DEG);
59 public HueRing(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
60 super(context, attrs, defStyleAttr);
61 init(Colors.DEFAULT_HUE_DEG);
63 public HueRing(Context context, @Nullable AttributeSet attrs, int defStyleAttr,
65 super(context, attrs, defStyleAttr, defStyleRes);
66 init(Colors.DEFAULT_HUE_DEG);
68 public HueRing(Context context) {
70 init(Colors.DEFAULT_HUE_DEG);
72 public HueRing(Context context, int initialHueDegrees) {
74 init(initialHueDegrees);
76 private void init(int initialHueDegrees) {
77 final int[] steps = {Colors.getPrimaryColorForHue(0), // red
78 Colors.getPrimaryColorForHue(60), // yellow
79 Colors.getPrimaryColorForHue(120), // green
80 Colors.getPrimaryColorForHue(180), // cyan
81 Colors.getPrimaryColorForHue(240), // blue
82 Colors.getPrimaryColorForHue(300), // magenta
83 Colors.getPrimaryColorForHue(360), // red, again
85 Shader rainbow = new SweepGradient(0, 0, steps, null);
87 ringPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
88 ringPaint.setShader(rainbow);
89 ringPaint.setStyle(Paint.Style.STROKE);
91 initialPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
92 initialPaint.setStyle(Paint.Style.FILL);
94 currentPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
95 currentPaint.setStyle(Paint.Style.FILL);
97 setInitialHue(initialHueDegrees);
98 setHue(initialHueDegrees);
100 markerStrokeWidth = DimensionUtils.dp2px(getContext(), 4);
102 padding = markerStrokeWidth * 2 + 2;
104 markerPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
105 markerPaint.setStyle(Paint.Style.STROKE);
106 markerPaint.setColor(0xa0000000);
107 markerPaint.setStrokeWidth(markerStrokeWidth);
109 public int getColor() {
112 public int getHueDegrees() {
115 public void setHue(int hueDegrees) {
116 if (hueDegrees == -1) hueDegrees = Colors.DEFAULT_HUE_DEG;
118 if (hueDegrees != Colors.DEFAULT_HUE_DEG) {
119 // round to 15 degrees
120 int rem = hueDegrees % hueStepDegrees;
121 if (rem < (hueStepDegrees / 2)) hueDegrees -= rem;
122 else hueDegrees += hueStepDegrees - rem;
125 this.hueDegrees = hueDegrees;
126 this.color = Colors.getPrimaryColorForHue(hueDegrees);
127 currentPaint.setColor(this.color);
130 private void setHue(float hue) {
131 setHue((int) (360f * hue));
134 protected void onDraw(Canvas canvas) {
135 super.onDraw(canvas);
137 float center = getWidth() / 2f;
138 ringPaint.setStrokeWidth((int) bandWidth);
141 canvas.translate(center, center);
142 canvas.drawOval(ringRect, ringPaint);
144 canvas.drawArc(centerRect, 180, 180, true, initialPaint);
145 canvas.drawArc(centerRect, 0, 180, true, currentPaint);
148 drawMarker(canvas, center);
150 private void drawMarker(Canvas canvas, float center) {
151 float leftRadians = (float) Math.toRadians(-hueStepDegrees / 2f);
152 float rightRadians = (float) Math.toRadians(hueStepDegrees / 2f);
153 float sl = (float) Math.sin(leftRadians);
154 float sr = (float) Math.sin(rightRadians);
155 float cl = (float) Math.cos(leftRadians);
156 float cr = (float) Math.cos(rightRadians);
157 float innerEdge = innerR - 1.5f * markerStrokeWidth;
158 float outerEdge = outerR + 1.5f + markerStrokeWidth;
160 // p.arcTo(-innerEdge, -innerEdge, innerEdge, innerEdge, -hueStepDegrees / 2f,
161 // hueStepDegrees, true);
162 // p.lineTo(outerEdge * cr, outerEdge * sr);
163 p.arcTo(-outerEdge, -outerEdge, outerEdge, outerEdge, hueStepDegrees / 2f,
164 -hueStepDegrees, false);
167 canvas.translate(center, center);
168 canvas.rotate(hueDegrees, 0, 0);
169 canvas.drawPath(p, markerPaint);
173 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
174 int widthMode = View.MeasureSpec.getMode(widthMeasureSpec);
175 int widthSize = View.MeasureSpec.getSize(widthMeasureSpec);
176 int heightMode = View.MeasureSpec.getMode(heightMeasureSpec);
177 int heightSize = View.MeasureSpec.getSize(heightMeasureSpec);
179 if ((widthMode == MeasureSpec.AT_MOST) && (heightMode == MeasureSpec.AT_MOST)) {
180 diameter = Math.min(widthSize, heightSize);
183 setMeasuredDimension(MEASURED_STATE_TOO_SMALL, MEASURED_STATE_TOO_SMALL);
187 setMeasuredDimension(diameter, diameter);
189 // padding = DimensionUtils.dp2px(getContext(),
190 // getContext().getResources().getDimension(R.dimen.activity_horizontal_margin)) / 2;
191 diameter -= 2 * padding;
192 outerR = diameter / 2f;
193 centerX = padding + (int) outerR;
196 bandWidth = diameter / 3.5f;
197 ringR = outerR - bandWidth / 2f;
198 innerR = outerR - bandWidth;
200 ringRect = new RectF(-ringR, -ringR, ringR, ringR);
202 innerDiameter = diameter - 2 * bandWidth;
203 centerR = innerDiameter * 0.5f;
204 centerRect = new RectF(-centerR, -centerR, centerR, centerR);
207 public boolean onTouchEvent(MotionEvent event) {
208 switch (event.getAction()) {
209 case MotionEvent.ACTION_DOWN:
210 case MotionEvent.ACTION_MOVE:
211 float x = event.getX() - centerX;
212 float y = event.getY() - centerY;
214 float dist = (float) Math.hypot(x, y);
216 if (dist < centerR) {
218 setHue(initialHueDegrees);
223 float angleRad = (float) Math.atan2(y, x);
224 // angleRad is [-𝜋; +𝜋]
225 float hue = (float) (angleRad / (2 * Math.PI));
226 if (hue < 0) hue += 1;
228 String.format("x=%1.3f, y=%1.3f, angle=%1.3frad, hueDegrees=%1.3f", x, y,
236 public void setInitialHue(int initialHue) {
237 if (initialHue == -1) initialHue = Colors.DEFAULT_HUE_DEG;
238 this.initialHueDegrees = initialHue;
239 this.initialPaint.setColor(Colors.getPrimaryColorForHue(initialHue));