you should overried onlayout and onmeasure without that it wont work, it gives the size to your component.
Look into creating custom view first. http://developer.android.com/intl/de/guide/topics/ui/custom-components.html On Mon, Apr 19, 2010 at 3:00 PM, zebdor <[email protected]> wrote: > Hello, > > I hope this question belongs in the Android Developers and not Android > Beginners group but I have a question about ScrollViews. I am > currently working with a customized GraphView class and am trying to > put it into a ScrollView but it doesn't seem to work. Whenever I run > the code, it comes up with a blank screen. I've written the code in > XML and also tried to create the ScrollView encapsulating the > GraphView programmatically but whenever the code runs, it comes up > with just a blank screen and GraphView's onDraw() is never called. > > Here's the code (with XML file): > > GraphView.java: > public class GraphView extends View { > > private Paint paint; > private float[] values; > private String[] horlabels; > private String[] verlabels; > private String title; > > public GraphView(Context context, AttributeSet attributeSet) { > super(context, attributeSet); > > title = "Graph"; > float[] values = new float[] { 2.0f, 1.5f, 2.5f, 1.0f, > 3.0f }; > String[] verlabels = new String[] { "great", "ok", "bad" }; > String[] horlabels = new String[] { "today", "tomorrow", > "next week", "next month" }; > > if (values == null) > values = new float[0]; > else > this.values = values; > > if (horlabels == null) > this.horlabels = new String[0]; > else > this.horlabels = horlabels; > if (verlabels == null) > this.verlabels = new String[0]; > else > this.verlabels = verlabels; > paint = new Paint(); > } > > @Override > protected void onDraw(Canvas canvas) { > float border = 20; > float horstart = border * 2; > float height = getHeight(); > float width = getWidth() - 1; > float max = getMax(); > float min = getMin(); > float diff = max - min; > float graphheight = height - (2 * border); > float graphwidth = width - (2 * border); > > paint.setTextAlign(Align.LEFT); > int vers = verlabels.length - 1; > for (int i = 0; i < verlabels.length; i++) { > paint.setColor(Color.DKGRAY); > float y = ((graphheight / vers) * i) + border; > canvas.drawLine(horstart, y, width, y, paint); > paint.setColor(Color.WHITE); > canvas.drawText(verlabels[i], 0, y, paint); > } > int hors = horlabels.length - 1; > for (int i = 0; i < horlabels.length; i++) { > paint.setColor(Color.DKGRAY); > float x = ((graphwidth / hors) * i) + horstart; > canvas.drawLine(x, height - border, x, border, paint); > paint.setTextAlign(Align.CENTER); > if (i==horlabels.length-1) > paint.setTextAlign(Align.RIGHT); > if (i==0) > paint.setTextAlign(Align.LEFT); > paint.setColor(Color.WHITE); > canvas.drawText(horlabels[i], x, height - 4, paint); > } > > paint.setTextAlign(Align.CENTER); > canvas.drawText(title, (graphwidth / 2) + horstart, border - > 4, paint); > > float colwidth = (width - (horstart)) / (horlabels.length - > 1); > float lasth = 0; > for (int i = 0; i < values.length; i++) { > float val = values[i] - min; > float rat = val / diff; > float h = graphheight * rat; > if (i > 0) > canvas.drawLine(((i - 1) * colwidth) + horstart, > (border - lasth) + graphheight, (i * colwidth) + horstart, (border - > h) + graphheight, paint); > lasth = h; > } > } > > private float getMax() { > float largest = Integer.MIN_VALUE; > for (int i = 0; i < values.length; i++) > if (values[i] > largest) > largest = values[i]; > return largest; > } > > private float getMin() { > float smallest = Integer.MAX_VALUE; > for (int i = 0; i < values.length; i++) > if (values[i] < smallest) > smallest = values[i]; > return smallest; > } > } > > > Graph.java: > public class Graph extends Activity { > /** Called when the activity is first created. */ > @Override > public void onCreate(Bundle savedInstanceState) { > super.onCreate(savedInstanceState); > setContentView(R.layout.main); > } > } > > > main.xml: > <?xml version="1.0" encoding="utf-8"?> > <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"; > android:layout_width="fill_parent" > android:layout_height="fill_parent" > > > <com.examples.graph.GraphView android:layout_width="fill_parent" > android:layout_height="fill_parent" > /> > </ScrollView> > > > > Any help would be greatly appreciated! Thanks! > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected]<android-developers%[email protected]> > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
