Android color picking

/*
* Copyright (c) 2007 the android open source project
*
* Licensed under the Apache license, version 2.0 (the "License ");
* You may not use this file before t in compliance with the license.
* You may obtain a copy of the license
*
* Http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* Distributed under the license is distributed on an "as is" basis,
* Without warranties or conditions of any kind, either express or implied.
* See the license for the specific language governing permissions and
* Limitations under the license.
*/

Package com. example. Android. APIs. graphics;

Import Android. OS. Bundle;
Import Android. App. Dialog;
Import Android. content. context;
Import Android. Graphics .*;
Import Android. View. motionevent;
Import Android. View. view;

Public class colorpickerdialog extends dialog {

Public interface oncolorchangedlistener {
Void colorchanged (INT color );
}

Private oncolorchangedlistener mlistener;
Private int minitialcolor;

Private Static class colorpickerview extends view {
Private paint mpaint;
Private paint mcenterpaint;
Private Final int [] mcolors;
Private oncolorchangedlistener mlistener;

Colorpickerview (context c, oncolorchangedlistener L, int color ){
Super (C );
Mlistener = L;
Mcolors = new int [] {
0xffff0000, 0xffff00ff, 0xff0000ff, 0xff00ffff, 0xff00ff00,
0xffffff00, 0xffff0000
};
Shader S = new sweepgradient (0, 0, mcolors, null );

Mpaint = new paint (paint. anti_alias_flag );
Mpaint. setshader (s );
Mpaint. setstyle (paint. style. Stroke );
Mpaint. setstrokewidth (32 );

Mcenterpaint = new paint (paint. anti_alias_flag );
Mcenterpaint. setcolor (color );
Mcenterpaint. setstrokewidth (5 );
}

Private Boolean mtrackingcenter;
Private Boolean mhighlightcenter;

@ Override
Protected void ondraw (canvas ){
Float r = center_x-mpaint. getstrokewidth () * 0.5f;

Canvas. Translate (center_x, center_x );

Canvas. drawoval (New rectf (-R,-R, R, R), mpaint );
Canvas. drawcircle (0, 0, center_radius, mcenterpaint );

If (mtrackingcenter ){
Int c = mcenterpaint. getcolor ();
Mcenterpaint. setstyle (paint. style. Stroke );

If (mhighlightcenter ){
Mcenterpaint. setalpha (0xff );
} Else {
Mcenterpaint. setalpha (0x80 );
}
Canvas. drawcircle (0, 0,
Center_radius + mcenterpaint. getstrokewidth (),
Mcenterpaint );

Mcenterpaint. setstyle (paint. style. Fill );
Mcenterpaint. setcolor (C );
}
}

@ Override
Protected void onmeasure (INT widthmeasurespec, int heightmeasurespec ){
Setmeasureddimension (center_x * 2, center_y * 2 );
}

Private Static final int center_x = 100;
Private Static final int center_y = 100;
Private Static final int center_radius = 32;

Private int floattobyte (float X ){
Int n = java. Lang. Math. Round (X );
Return N;
}
Private int pintobyte (int n ){
If (n <0 ){
N = 0;
} Else if (n> 255 ){
N = 255;
}
Return N;
}

Private int ave (int s, int D, float p ){
Return S + Java. Lang. Math. Round (p * (d-s ));
}

Private int interpcolor (INT colors [], float unit ){
If (Unit <= 0 ){
Return colors [0];
}
If (unit> = 1 ){
Return colors [colors. Length-1];
}

Float P = unit * (colors. Length-1 );
Int I = (INT) P;
P-= I;

// Now P is just the fractional part [0... 1) and I is the index
Int C0 = colors [I];
Int C1 = colors [I + 1];
Int A = ave (color. Alpha (C0), color. Alpha (C1), P );
Int r = ave (color. Red (C0), color. Red (C1), P );
Int G = ave (color. Green (C0), color. Green (C1), P );
Int B = ave (color. Blue (C0), color. Blue (C1), P );

Return color. argb (A, R, G, B );
}

Private int rotatecolor (INT color, float rad ){
Float deg = rad * 180/3 .1415927f;
Int r = color. Red (color );
Int G = color. Green (color );
Int B = color. Blue (color );

Colormatrix CM = new colormatrix ();
Colormatrix TMP = new colormatrix ();

Cm. setrgb2yuv ();
TMP. setrotate (0, deg );
Cm. postconcat (TMP );
TMP. setyuv2rgb ();
Cm. postconcat (TMP );

Final float [] A = cm. getarray ();

Int IR = floattobyte (A [0] * r + A [1] * g + A [2] * B );
Int ig = floattobyte (A [5] * r + A [6] * g + A [7] * B );
Int IB = floattobyte (A [10] * r + A [11] * g + A [12] * B );

Return color. argb (color. Alpha (color), pintobyte (IR ),
Pintobyte (IG), pintobyte (IB ));
}

Private Static final float Pi = 3.1415926f;

@ Override
Public Boolean ontouchevent (motionevent event ){
Float x = event. getx ()-center_x;
Float y = event. Gety ()-center_y;
Boolean incenter = java. Lang. Math. SQRT (x * x + y * Y) <= center_radius;

Switch (event. getaction ()){
Case motionevent. action_down:
Mtrackingcenter = incenter;
If (incenter ){
Mhighlightcenter = true;
Invalidate ();
Break;
}
Case motionevent. action_move:
If (mtrackingcenter ){
If (mhighlightcenter! = Incenter ){
Mhighlightcenter = incenter;
Invalidate ();
}
} Else {
Float angle = (float) Java. Lang. Math. atan2 (Y, X );
// Need to turn angle [-pi... Pi] into Unit [0... 1]
Float unit = angle/(2 * PI );
If (Unit <0 ){
Unit + = 1;
}
Mcenterpaint. setcolor (interpcolor (mcolors, unit ));
Invalidate ();
}
Break;
Case motionevent. action_up:
If (mtrackingcenter ){
If (incenter ){
Mlistener. colorchanged (mcenterpaint. getcolor ());
}
Mtrackingcenter = false; // so we draw w/o halo
Invalidate ();
}
Break;
}
Return true;
}
}

Public colorpickerdialog (context,
Oncolorchangedlistener listener,
Int initialcolor ){
Super (context );

Mlistener = listener;
Minitialcolor = initialcolor;
}

@ Override
Protected void oncreate (bundle savedinstancestate ){
Super. oncreate (savedinstancestate );
Oncolorchangedlistener L = new oncolorchangedlistener (){
Public void colorchanged (INT color ){
Mlistener. colorchanged (color );
Dismiss ();
}
};

Setcontentview (New colorpickerview (getcontext (), L, minitialcolor ));
Settitle ("pick a color ");
}
}