View グループから拡張された View を使用していますが、invalidate を呼び出したときに onDraw が呼び出されません。説明してください。コードを以下に示します
public class BarGraph extends View {
private int viewHeight;
private int viewWidth; // height and width of bar graph dynamically calculated.
private int mGraphColor; // the colour of the bar graph.
private ArrayList<Integer> mTodays; // The array list that handles the input to draw the graph.
private final int barCount = 20; // Number of bars in the bar graph...here set as 20.
/*
* The maximum action value a bar can take.
* This is calculated based on the action array
* passed to the chart.
*/
private int yMax = 0;
private Paint graphColor;
public BarGraph(Context context, int graphColor) {
super(context);
this.setWillNotDraw(false);
mGraphColor = graphColor;
setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
initializePaintObjects();
}
public BarGraph(Context context, AttributeSet attrs) {
super(context, attrs);
this.setWillNotDraw(false);
initializePaintObjects();
}
private void initializePaintObjects(){
graphColor = new Paint();
graphColor.setColor(mGraphColor);
graphColor.setStyle(Style.FILL);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(mTodays == null) // If the array list is empty.
return;
if(yMax <= 0)
return;
int left = 0;
viewHeight = getHeight();
viewWidth = getWidth();
if((viewWidth % barCount) > 0){ //adjusting the view width so that bars correctly fits in
int newWidth = (int) (Math.floor(viewWidth / barCount) * barCount);
left = (int) Math.floor(((viewWidth - newWidth)/2));
viewWidth = (int) Math.floor((viewWidth / barCount) * barCount);
}
int columnWidth = 2;
columnWidth = (int) Math.floor(viewWidth / barCount);
int xFactor = 1;
xFactor = (int) Math.ceil(columnWidth * 0.33);
int barWidth = 1;
barWidth = columnWidth - xFactor;
graphColor.setStrokeWidth(barWidth);
int j = 0;
for(int i = 0; i < mTodays.size() ; i++){
int todayValue = mTodays.get(i);
float todaysHeight;
if(todayValue == 0){
todaysHeight = (float) (viewHeight-viewHeight*(.001));
}else{
todaysHeight = getYValue(todayValue);
}
canvas.drawLine(((j*columnWidth)+xFactor + left) , viewHeight, ((j*columnWidth)+xFactor + left), todaysHeight, graphColor);
j++;
}
}
public void setData(ArrayList<Integer>todays){
mTodays = todays;
yMax = 0;
for (int val : mTodays){
yMax = yMax > val ? yMax : val;
}
invalidate();
}
private int getYValue(int item){
int percent = (item * 100)/yMax;
return (viewHeight) - ((percent * viewHeight)/100);
}
}