I&#39;m writing a few custom views which share some same-named attributes. In their respective `&lt;declare-styleable&gt;` section in `attrs.xml` I&#39;d like to use the same names for attributes:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;resources&gt;
        &lt;declare-styleable name=&quot;MyView1&quot;&gt;
            &lt;attr name=&quot;myattr1&quot; format=&quot;string&quot; /&gt;
            &lt;attr name=&quot;myattr2&quot; format=&quot;dimension&quot; /&gt;
            ...
        &lt;/declare-styleable&gt;
    
        &lt;declare-styleable name=&quot;MyView2&quot;&gt;
            &lt;attr name=&quot;myattr1&quot; format=&quot;string&quot; /&gt;
            &lt;attr name=&quot;myattr2&quot; format=&quot;dimension&quot; /&gt;
            ...
        &lt;/declare-styleable&gt;
    &lt;/resources&gt;

I&#39;m getting an error saying that `myattr1` and `myattr2` are already defined. I found that I should omit the `format` attribute for `myattr1` and `myattr2` in `MyView2`, but if I do that, I obtain the following error in the console:

    [2010-12-13 23:53:11 - MyProject] ERROR: In &lt;declare-styleable&gt; MyView2, unable to find attribute 

Is there a way I could accomplish this, maybe some sort of namespacing (just guessing)?

Same-named attributes in attrs.xml for custom view

**What I am trying to do:** I am trying to make a custom dialog in android With rounded corners.

**What is happening:** I am able to make custom dialog but it doesn&#39;t have rounded corners. I tried adding a selector but still I couldn&#39;t achieve rounded corners.

Below is my code for the same:


----------


**Java code:** 

    private void launchDismissDlg() {
    		
    		dialog = new Dialog(getActivity(), android.R.style.Theme_Dialog);
    		dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    		dialog.setContentView(R.layout.dlg_dismiss);
    		dialog.setCanceledOnTouchOutside(true);
    		
    		Button btnReopenId = (Button) dialog.findViewById(R.id.btnReopenId);
    		Button btnCancelId = (Button) dialog.findViewById(R.id.btnCancelId);
    
    		btnReopenId.setOnClickListener(new OnClickListener() {
    			@Override
    			public void onClick(View v) {
    				
    				
    				
    			}
    		});
    
    		
    		btnCancelId.setOnClickListener(new OnClickListener() {
    			@Override
    			public void onClick(View v) {
    				
    				
    				
    			}
    		});
    		dialog.setCanceledOnTouchOutside(false);
    		dialog.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
    		dialog.getWindow().setLayout(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT);
    		dialog.show();
    		
    	}

**xml code:**

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;LinearLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        android:background=&quot;@android:color/white&quot;
        android:orientation=&quot;vertical&quot; &gt;
    
        &lt;TableLayout
            android:layout_width=&quot;match_parent&quot;
            android:layout_height=&quot;wrap_content&quot; &gt;
    
            &lt;TableRow
                android:id=&quot;@+id/tableRow1&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;wrap_content&quot;
                android:layout_marginTop=&quot;20dp&quot;
                android:gravity=&quot;center&quot; &gt;
    
                &lt;TextView
                    android:id=&quot;@+id/textView1&quot;
                    android:layout_width=&quot;wrap_content&quot;
                    android:layout_height=&quot;wrap_content&quot;
                    android:gravity=&quot;center&quot;
                    android:text=&quot;&amp;quot;I WOULD LIKE TO DISMISS THE VENDOR&amp;quot;&quot;
                    android:textColor=&quot;@color/col_dlg_blue_light&quot;
                    android:textSize=&quot;14sp&quot;
                    android:textStyle=&quot;bold&quot; /&gt;
            &lt;/TableRow&gt;
    
            &lt;TableRow
                android:id=&quot;@+id/tableRow2&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;wrap_content&quot;
                android:layout_marginTop=&quot;5dp&quot;
                android:gravity=&quot;center&quot; &gt;
    
                &lt;TextView
                    android:id=&quot;@+id/textView2&quot;
                    android:layout_width=&quot;wrap_content&quot;
                    android:layout_height=&quot;wrap_content&quot;
                    android:gravity=&quot;center&quot;
                    android:text=&quot;BECAUSE&quot;
                    android:textColor=&quot;@android:color/black&quot;
                    android:textStyle=&quot;bold&quot; /&gt;
            &lt;/TableRow&gt;
    
          
    
            &lt;TableRow
                android:id=&quot;@+id/tableRow4&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;wrap_content&quot; &gt;
    
                &lt;Button
                    android:id=&quot;@+id/btnReopenId&quot;
                    android:layout_width=&quot;0dp&quot;
                    android:layout_height=&quot;wrap_content&quot;
                    android:layout_weight=&quot;1&quot;
                    android:background=&quot;@color/col_dlg_green_light&quot;
                    android:text=&quot;REOPEN&quot;
                    android:padding=&quot;5dp&quot;
                    android:textSize=&quot;14sp&quot;
                    android:textColor=&quot;@android:color/white&quot;
                    android:textStyle=&quot;bold&quot; /&gt;
    
                &lt;Button
                    android:id=&quot;@+id/btnCancelId&quot;
                    android:layout_width=&quot;0dp&quot;
                    android:layout_height=&quot;wrap_content&quot;
                    android:layout_weight=&quot;1&quot;
                    android:background=&quot;@color/col_dlg_pink_light&quot;
                    android:text=&quot;CANCEL&quot;
                    android:padding=&quot;5dp&quot;
                    android:textSize=&quot;14sp&quot;
                    android:textColor=&quot;@android:color/white&quot;
                    android:textStyle=&quot;bold&quot; /&gt;
            &lt;/TableRow&gt;
        &lt;/TableLayout&gt;
    
    &lt;/LinearLayout&gt;

How to make custom dialog with rounded corners in android

When creating a custom view, I have noticed that many people seem to do it like this:

    public MyView(Context context) {
      super(context);
      // this constructor used when programmatically creating view
      doAdditionalConstructorWork();
    }
    
    public MyView(Context context, AttributeSet attrs) {
      super(context, attrs);
      // this constructor used when creating view through XML
      doAdditionalConstructorWork();
    }

    private void doAdditionalConstructorWork() {

      // init variables etc.
    }


My first question is, what about the constructor `MyView(Context context, AttributeSet attrs, int defStyle)`?  I&#39;m not sure where it is used, but I see it in the super class.  Do I need it, and where is it used?

There&#39;s [another part to this question][1].

  [1]: https://stackoverflow.com/questions/9195785/should-i-call-super-or-call-this-for-android-custom-view-constructors

Do I need all three constructors for an Android custom view?

I created a custom View (find it [here][1]) with an declare-styleable attribute of type enum. In xml I can now choose one of the enum entries for my custom attribute. Now I want to create an method to set this value programmatically, but I can not access the enum. 

**attr.xml**

    &lt;declare-styleable name=&quot;IconView&quot;&gt;
        &lt;attr name=&quot;icon&quot; format=&quot;enum&quot;&gt;
            &lt;enum name=&quot;enum_name_one&quot; value=&quot;0&quot;/&gt;
            ....
            &lt;enum name=&quot;enum_name_n&quot; value=&quot;666&quot;/&gt;
       &lt;/attr&gt;
    &lt;/declare-styleable&gt;     

**layout.xml**

    &lt;com.xyz.views.IconView
        android:id=&quot;@+id/heart_icon&quot;
        android:layout_width=&quot;wrap_content&quot;
        android:layout_height=&quot;wrap_content&quot;
        app:icon=&quot;enum_name_x&quot;/&gt;

What I need is something like: `mCustomView.setIcon(R.id.enum_name_x);`
But I can not find the enum or I even have no idea how I can get the enum or the names of the enum. 

  [1]: https://bitbucket.org/informatic0re/awesome-font-iconview

How to get an enum which is created in attrs.xml in code

Is there any method to change the layout of a snackBar to custom View?

Now it comes black and we can change the background color.
But I don&#39;t know the right way to inflate a new layout and making it as snackBars background?

Thanks...


how to customize snackBar&#39;s layout?

I must edit a software that have a custom view, when I try to edit layout xml, Eclipse says me: 

&gt; Use View.isInEditMode() in your custom views to skip code when shown
&gt; in Eclipse

But I have no idea about *how* and *where* I must use *isInEditMode()* in the app



My xml file is



    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;LinearLayout 
         xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
         android:orientation=&quot;vertical&quot;
         android:layout_width=&quot;fill_parent&quot;
         android:layout_height=&quot;fill_parent&quot;
         android:background=&quot;#ff000000&quot;
        &gt;
    &lt;TextView
         android:id=&quot;@+id/result&quot;
         android:layout_width=&quot;fill_parent&quot; 
         android:layout_height=&quot;wrap_content&quot;
         android:gravity=&quot;right&quot;
         android:textSize=&quot;32dip&quot;
         android:scrollbars=&quot;none&quot;
         android:lines=&quot;1&quot;
         android:freezesText=&quot;true&quot;
         android:textColor=&quot;@color/result&quot;
        /&gt;
    &lt;EditText
         android:id=&quot;@+id/input&quot;
         android:layout_width=&quot;fill_parent&quot;
         android:layout_height=&quot;wrap_content&quot;
         android:gravity=&quot;left&quot;
         android:textSize=&quot;28dip&quot;
         android:scrollbars=&quot;none&quot;
         android:singleLine=&quot;true&quot;
         android:autoText=&quot;false&quot;
         android:imeOptions=&quot;flagNoEnterAction|flagNoExtractUi&quot;
         /&gt;
    &lt;ListView
         android:id=&quot;@+id/history&quot;
         android:layout_width=&quot;fill_parent&quot;
         android:layout_height=&quot;0dip&quot;
         android:layout_weight=&quot;1&quot;
         android:cacheColorHint=&quot;#ff000000&quot;
         android:choiceMode=&quot;singleChoice&quot;
         android:scrollbarStyle=&quot;outsideInset&quot;
         android:scrollbars=&quot;none&quot;
        /&gt;
    &lt;calculator.GraphView
         android:id=&quot;@+id/graph&quot;
         android:layout_width=&quot;fill_parent&quot;
         android:layout_height=&quot;0dip&quot;
         android:layout_weight=&quot;1&quot;
         android:visibility=&quot;gone&quot;
         /&gt;
    &lt;include layout=&quot;@layout/keyboard&quot; /&gt;
    &lt;/LinearLayout&gt;


And my GraphView is

    public class GraphView extends View implements Grapher,
    		ZoomButtonsController.OnZoomListener,
    		TouchHandler.TouchHandlerInterface {
    	private int width, height;
    	private Matrix matrix = new Matrix();
    	private Paint paint = new Paint();
    	private Paint textPaint = new Paint();
    	private ArrayList&lt;Function&gt; funcs = new ArrayList&lt;Function&gt;();
    	private Data next = new Data(), endGraph = new Data();
    	private Data graphs[] = { new Data(), new Data(), new Data(), new Data(),
    			new Data() };
    	private static final int GRAPHS_SIZE = 5;
    	private float gwidth = 8;
    	private float currentX, currentY;
    	private float lastMinX;
    	private Scroller scroller;
    	private float boundMinY, boundMaxY;
    	protected ZoomButtonsController zoomController = new ZoomButtonsController(
    			this);
    	private ZoomTracker zoomTracker = new ZoomTracker();
    	private TouchHandler touchHandler;
    	private float lastTouchX, lastTouchY;
    
    	private static final int COL_AXIS = 0xff00a000, COL_GRID = 0xff004000,
    			COL_TEXT = 0xff00ff00;
    
    	private static final int COL_GRAPH[] = { 0xffffffff, 0xff00ffff,
    			0xffffff00, 0xffff00ff, 0xff80ff80 };
    
    	public GraphView(Context context, AttributeSet attrs) {
    		super(context, attrs);
    		init(context);
    	}
    
    	public GraphView(Context context) {
    		super(context);
    		touchHandler = new TouchHandler(this);
    		init(context);
    	}
    
    	private void init(Context context) {
    		zoomController.setOnZoomListener(this);
    		scroller = new Scroller(context);
    		paint.setAntiAlias(false);
    		textPaint.setAntiAlias(true);
    	}
    
    	@SuppressLint(&quot;WrongCall&quot;)
    	public String captureScreenshot() {
    		Bitmap bitmap = Bitmap.createBitmap(width, height,
    				Bitmap.Config.RGB_565);
    		Canvas canvas = new Canvas(bitmap);
    		onDraw(canvas);
    		return Util.saveBitmap(bitmap, Grapher.SCREENSHOT_DIR, &quot;calculator&quot;);
    	}
    
    	private void clearAllGraph() {
    		for (int i = 0; i &lt; GRAPHS_SIZE; ++i) {
    			graphs[i].clear();
    		}
    	}
    
    	public void setFunctions(ArrayList&lt;Function&gt; fs) {
    		funcs.clear();
    		for (Function f : fs) {
    			int arity = f.arity();
    			if (arity == 0 || arity == 1) {
    				funcs.add(f);
    			}
    		}
    		clearAllGraph();
    		invalidate();
    	}
    
    	public void setFunction(Function f) {
    		funcs.clear();
    		if (f != null) {
    			funcs.add(f);
    		}
    		clearAllGraph();
    		invalidate();
    	}
    
    	public void onVisibilityChanged(boolean visible) {
    	}
    
    	public void onZoom(boolean zoomIn) {
    		if (zoomIn) {
    			if (canZoomIn()) {
    				gwidth /= 2;
    				invalidateGraphs();
    			}
    		} else {
    			if (canZoomOut()) {
    				gwidth *= 2;
    				invalidateGraphs();
    			}
    		}
    		zoomController.setZoomInEnabled(canZoomIn());
    		zoomController.setZoomOutEnabled(canZoomOut());
    	}
    
    	public void onResume() {
    	}
    
    	public void onPause() {
    	}
    
    	public void onDetachedFromWindow() {
    		zoomController.setVisible(false);
    		super.onDetachedFromWindow();
    	}
    
    	protected void onSizeChanged(int w, int h, int ow, int oh) {
    		width = w;
    		height = h;
    		clearAllGraph();
    	}
    
    	protected void onDraw(Canvas canvas) {
    		if (funcs.size() == 0) {
    			return;
    		}
    		if (scroller.computeScrollOffset()) {
    			final float scale = gwidth / width;
    			currentX = scroller.getCurrX() * scale;
    			currentY = scroller.getCurrY() * scale;
    			if (!scroller.isFinished()) {
    				invalidate();
    			}
    		}
    		drawGraph(canvas);
    	}
    
    	private float eval(Function f, float x) {
    		float v = (float) f.eval(x);
    
    		if (v &lt; -10000f) {
    			return -10000f;
    		}
    		if (v &gt; 10000f) {
    			return 10000f;
    		}
    		return v;
    	}
    
    	private float distance2(float x1, float y1, float x2, float y2, float y) {
    		final float dx = x2 - x1;
    		final float dy = y2 - y1;
    		final float up = dx * (y1 + y2 - y - y);
    		return up * up / (dx * dx + dy * dy);
    	}
    
    	private void computeGraph(Function f, float minX, float maxX, float minY,
    			float maxY, Data graph) {
    		if (f.arity() == 0) {
    			float v = (float) f.eval();
    			if (v &lt; -10000f) {
    				v = -10000f;
    			}
    			if (v &gt; 10000f) {
    				v = 10000f;
    			}
    			graph.clear();
    			graph.push(minX, v);
    			graph.push(maxX, v);
    			return;
    		}
    
    		final float scale = width / gwidth;
    		final float maxStep = 15.8976f / scale;
    		final float minStep = .05f / scale;
    		float ythresh = 1 / scale;
    		ythresh = ythresh * ythresh;
    		if (!graph.empty()) {
    			if (minX &gt;= lastMinX) {
    				graph.eraseBefore(minX);
    			} else {
    				graph.eraseAfter(maxX);
    				maxX = Math.min(maxX, graph.firstX());
    				graph.swap(endGraph);
    			}
    		}
    		if (graph.empty()) {
    			graph.push(minX, eval(f, minX));
    		}
    		float leftX, leftY;
    		float rightX = graph.topX(), rightY = graph.topY();
    		int nEval = 1;
    		while (true) {
    			leftX = rightX;
    			leftY = rightY;
    			if (leftX &gt; maxX) {
    				break;
    			}
    			if (next.empty()) {
    				float x = leftX + maxStep;
    				next.push(x, eval(f, x));
    				++nEval;
    			}
    			rightX = next.topX();
    			rightY = next.topY();
    			next.pop();
    
    			if (leftY != leftY &amp;&amp; rightY != rightY) { // NaN
    				continue;
    			}
    
    			float dx = rightX - leftX;
    			float middleX = (leftX + rightX) / 2;
    			float middleY = eval(f, middleX);
    			++nEval;
    			boolean middleIsOutside = (middleY &lt; leftY &amp;&amp; middleY &lt; rightY)
    					|| (leftY &lt; middleY &amp;&amp; rightY &lt; middleY);
    			if (dx &lt; minStep) {
    				if (middleIsOutside) {
    					graph.push(rightX, Float.NaN);
    				}
    				graph.push(rightX, rightY);
    				continue;
    			}
    			if (middleIsOutside
    					&amp;&amp; ((leftY &lt; minY &amp;&amp; rightY &gt; maxY) || (leftY &gt; maxY &amp;&amp; rightY &lt; minY))) {
    				graph.push(rightX, Float.NaN);
    				graph.push(rightX, rightY);
    				continue;
    			}
    
    			if (!middleIsOutside) {
    
    				if (distance2(leftX, leftY, rightX, rightY, middleY) &lt; ythresh) {
    					graph.push(rightX, rightY);
    					continue;
    				}
    			}
    			next.push(rightX, rightY);
    			next.push(middleX, middleY);
    			rightX = leftX;
    			rightY = leftY;
    		}
    		if (!endGraph.empty()) {
    			graph.append(endGraph);
    		}
    		long t2 = System.currentTimeMillis();
    
    		next.clear();
    		endGraph.clear();
    	}
    
    	private static Path path = new Path();
    
    	private Path graphToPath(Data graph) {
    		boolean first = true;
    		int size = graph.size;
    		float[] xs = graph.xs;
    		float[] ys = graph.ys;
    		path.rewind();
    		for (int i = 0; i &lt; size; ++i) {
    			float y = ys[i];
    			float x = xs[i];
    			// Calculator.log(&quot;path &quot; + x + &#39; &#39; + y);
    			if (y == y) { // !NaN
    				if (first) {
    					path.moveTo(x, y);
    					first = false;
    				} else {
    					path.lineTo(x, y);
    				}
    			} else {
    				first = true;
    			}
    		}
    		return path;
    	}
    
    	private static final float NTICKS = 15;
    
    	private static float stepFactor(float w) {
    		float f = 1;
    		while (w / f &gt; NTICKS) {
    			f *= 10;
    		}
    		while (w / f &lt; NTICKS / 10) {
    			f /= 10;
    		}
    		float r = w / f;
    		if (r &lt; NTICKS / 5) {
    			return f / 5;
    		} else if (r &lt; NTICKS / 2) {
    			return f / 2;
    		} else {
    			return f;
    		}
    	}
    
    	private static StringBuilder b = new StringBuilder();
    	private static char[] buf = new char[20];
    
    	private static StringBuilder format(float fv) {
    		int pos = 0;
    		boolean addDot = false;
    		int v = Math.round(fv * 100);
    		boolean isNeg = v &lt; 0;
    		v = isNeg ? -v : v;
    		for (int i = 0; i &lt; 2; ++i) {
    			int digit = v % 10;
    			v /= 10;
    			if (digit != 0 || addDot) {
    				buf[pos++] = (char) (&#39;0&#39; + digit);
    				addDot = true;
    			}
    		}
    		if (addDot) {
    			buf[pos++] = &#39;.&#39;;
    		}
    		if (v == 0) {
    			buf[pos++] = &#39;0&#39;;
    		}
    		while (v != 0) {
    			buf[pos++] = (char) (&#39;0&#39; + (v % 10));
    			v /= 10;
    		}
    		if (isNeg) {
    			buf[pos++] = &#39;-&#39;;
    		}
    		b.setLength(0);
    		b.append(buf, 0, pos);
    		b.reverse();
    		return b;
    	}
    
    	private void drawGraph(Canvas canvas) {
    		long t1 = System.currentTimeMillis();
    		float minX = currentX - gwidth / 2;
    		float maxX = minX + gwidth;
    		float ywidth = gwidth * height / width;
    		float minY = currentY - ywidth / 2;
    		float maxY = minY + ywidth;
    		if (minY &lt; boundMinY || maxY &gt; boundMaxY) {
    			float halfw = ywidth / 2;
    			boundMinY = minY - halfw;
    			boundMaxY = maxY + halfw;
    			clearAllGraph();
    		}
    
    		canvas.drawColor(0xff000000);
    
    		paint.setStrokeWidth(0);
    		paint.setAntiAlias(false);
    		paint.setStyle(Paint.Style.STROKE);
    
    		final float h2 = height / 2f;
    		final float scale = width / gwidth;
    
    		float x0 = -minX * scale;
    		boolean drawYAxis = true;
    		if (x0 &lt; 25) {
    			x0 = 25;
    			// drawYAxis = false;
    		} else if (x0 &gt; width - 3) {
    			x0 = width - 3;
    			// drawYAxis = false;
    		}
    		float y0 = maxY * scale;
    		if (y0 &lt; 3) {
    			y0 = 3;
    		} else if (y0 &gt; height - 15) {
    			y0 = height - 15;
    		}
    
    		final float tickSize = 3;
    		final float y2 = y0 + tickSize;
    		paint.setColor(COL_GRID);
    		float step = stepFactor(gwidth);
    		float v = ((int) (minX / step)) * step;
    		textPaint.setColor(COL_TEXT);
    		textPaint.setTextSize(12);
    		textPaint.setTextAlign(Paint.Align.CENTER);
    		float stepScale = step * scale;
    		for (float x = (v - minX) * scale; x &lt;= width; x += stepScale, v += step) {
    			canvas.drawLine(x, 0, x, height, paint);
    			if (!(-.001f &lt; v &amp;&amp; v &lt; .001f)) {
    				StringBuilder b = format(v);
    				canvas.drawText(b, 0, b.length(), x, y2 + 10, textPaint);
    			}
    		}
    
    		final float x1 = x0 - tickSize;
    		v = ((int) (minY / step)) * step;
    		textPaint.setTextAlign(Paint.Align.RIGHT);
    		for (float y = height - (v - minY) * scale; y &gt;= 0; y -= stepScale, v += step) {
    			canvas.drawLine(0, y, width, y, paint);
    			if (!(-.001f &lt; v &amp;&amp; v &lt; .001f)) {
    				StringBuilder b = format(v);
    				canvas.drawText(b, 0, b.length(), x1, y + 4, textPaint);
    			}
    		}
    
    		paint.setColor(COL_AXIS);
    		if (drawYAxis) {
    			canvas.drawLine(x0, 0, x0, height, paint);
    		}
    		canvas.drawLine(0, y0, width, y0, paint);
    
    		matrix.reset();
    		matrix.preTranslate(-currentX, -currentY);
    		matrix.postScale(scale, -scale);
    		matrix.postTranslate(width / 2, height / 2);
    
    		paint.setStrokeWidth(0);
    		paint.setAntiAlias(false);
    
    		int n = Math.min(funcs.size(), GRAPHS_SIZE);
    		for (int i = 0; i &lt; n; ++i) {
    			computeGraph(funcs.get(i), minX, maxX, boundMinY, boundMaxY,
    					graphs[i]);
    			Path path = graphToPath(graphs[i]);
    			path.transform(matrix);
    			paint.setColor(COL_GRAPH[i]);
    			canvas.drawPath(path, paint);
    		}
    		lastMinX = minX;
    	}
    
    	private boolean canZoomIn() {
    		return gwidth &gt; 1f;
    	}
    
    	private boolean canZoomOut() {
    		return gwidth &lt; 50;
    	}
    
    	private void invalidateGraphs() {
    		clearAllGraph();
    		boundMinY = boundMaxY = 0;
    		invalidate();
    	}
    
    	@Override
    	public boolean onTouchEvent(MotionEvent event) {
    		return touchHandler != null ? touchHandler.onTouchEvent(event) : super
    				.onTouchEvent(event);
    	}
    
    	public void onTouchDown(float x, float y) {
    		zoomController.setVisible(true);
    		if (!scroller.isFinished()) {
    			scroller.abortAnimation();
    		}
    		lastTouchX = x;
    		lastTouchY = y;
    	}
    
    	public void onTouchMove(float x, float y) {
    		float deltaX = x - lastTouchX;
    		float deltaY = y - lastTouchY;
    		if (deltaX &lt; -1 || deltaX &gt; 1 || deltaY &lt; -1 || deltaY &gt; 1) {
    			scroll(-deltaX, deltaY);
    			lastTouchX = x;
    			lastTouchY = y;
    			invalidate();
    		}
    	}
    
    	public void onTouchUp(float x, float y) {
    		final float scale = width / gwidth;
    		float sx = -touchHandler.velocityTracker.getXVelocity();
    		float sy = touchHandler.velocityTracker.getYVelocity();
    		final float asx = Math.abs(sx);
    		final float asy = Math.abs(sy);
    		if (asx &lt; asy / 3) {
    			sx = 0;
    		} else if (asy &lt; asx / 3) {
    			sy = 0;
    		}
    		scroller.fling(Math.round(currentX * scale),
    				Math.round(currentY * scale), Math.round(sx), Math.round(sy),
    				-10000, 10000, -10000, 10000);
    		invalidate();
    	}
    
    	public void onTouchZoomDown(float x1, float y1, float x2, float y2) {
    		zoomTracker.start(gwidth, x1, y1, x2, y2);
    	}
    
    	public void onTouchZoomMove(float x1, float y1, float x2, float y2) {
    		if (!zoomTracker.update(x1, y1, x2, y2)) {
    			return;
    		}
    		float targetGwidth = zoomTracker.value;
    		if (targetGwidth &gt; .25f &amp;&amp; targetGwidth &lt; 200) {
    			gwidth = targetGwidth;
    		}
    		invalidateGraphs();
    	}
    
    	private void scroll(float deltaX, float deltaY) {
    		final float scale = gwidth / width;
    		float dx = deltaX * scale;
    		float dy = deltaY * scale;
    		final float adx = Math.abs(dx);
    		final float ady = Math.abs(dy);
    		if (adx &lt; ady / 3) {
    			dx = 0;
    		} else if (ady &lt; adx / 3) {
    			dy = 0;
    		}
    		currentX += dx;
    		currentY += dy;
    	}
    }



The error Log of the XML editor

    java.lang.NullPointerException
        at android.widget.ZoomButtonsController.createContainer(ZoomButtonsController.java:266)
        at android.widget.ZoomButtonsController.&lt;init&gt;(ZoomButtonsController.java:212)
        at calculator.GraphView.&lt;init&gt;(GraphView.java:43)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(    at sun.reflect.NativeConstructorAccessorImpl.newInstance(    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(    at java.lang.reflect.Constructor.newInstance(    at com.android.ide.eclipse.adt.internal.editors.layout.ProjectCallback.instantiateClass(ProjectCallback.java:422)
        at com.android.ide.eclipse.adt.internal.editors.layout.ProjectCallback.loadView(ProjectCallback.java:179)
        at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:207)
        at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:135)
        at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:746)
        at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:718)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:372)



How to use isInEditMode() to see layout with custom View in the editor

**Edited Question:**

**Mobile Resolution:**&lt;br&gt; I would like to design different screen dpi like following resolutions. 
&lt;br&gt;320x480,&lt;br&gt;480&#215;800,&lt;br&gt;540x960,&lt;br&gt;720x1280 (Samsung S3),&lt;br&gt;1080x1920 (S4, Nexus5,Nexus 5x, Moto G4),&lt;br&gt;2560 x 1440 (Nexus 6, Nexus 6p, Samsung edge)&lt;br&gt;&lt;br&gt;
**Tablet Resolution:**&lt;br&gt; 480x800 (micromax) ,&lt;br&gt;600x1024 (samsung tab2),&lt;br&gt;800x1280 (nexus 7),&lt;br&gt;1200x1920 (new nexus 7),&lt;br&gt;2048x1536 (nexus 9)
 
I want to use **different font sizes** depending on the device display resolution. 

Q1) What is the `best` way to solve this `problem`?

Q2) What is best option doing throw coding or XML?

Q3) Which drawable folder is represent which device resolution?

Q4) Application Launcher icon size for different resolution?


Different resolution support android

View Binding got released as part of Android Jetpack

Docs: https://developer.android.com/topic/libraries/view-binding

My question is, how to use view binding with custom views. Google documentation has only show-cased Activity and fragment.

I tried this, but nothing was shown.

    LayoutInflater inflater = LayoutInflater.from(getContext());

And then, I used this one, but again, no luck.

    LayoutInflater inflater = (LayoutInflater)
                getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

 I guess maybe I don&#39;t target the correct layout inflater for my view but not sure.

How to use View Binding on custom views

The Fragment and Custom View can achieve the similar function, I know that fragment is more re-usable comparing with custom view, any other benefits/enhancements for using Fragment? Is fragment supposed to replace Custom View, or just a enhancement for some specific purpose? 

For instance, the code below is **fragment**: 

    public class TestFragment extends Fragment {
    	
    	private TextView tv_name;
    	private Button btn_play;
    	private Button btn_delete;
    	
    	@Override
    	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    		return inflater.inflate(R.layout.testfragment, container, false);
    	}
    	
    	@Override
    	public void onStart() {
    		super.onStart();
    		
    		tv_name = (TextView)getView().findViewById(R.id.tv_name);
    		btn_play = (Button)getView().findViewById(R.id.btn_play);
    		btn_delete = (Button)getView().findViewById(R.id.btn_delete);
    		
    	}
    }




The code for **custom view**: 

    public class TestCustomView extends LinearLayout {
    	
    	private TextView tv_name;
    	private Button btn_play;
    	private Button btn_delete;
    	
    	public TestCustomView(Context context, AttributeSet attrs){
    		super(context, attrs);
    
            setOrientation(LinearLayout.HORIZONTAL);
            setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
    
            tv_name = new TextView(context);
            addView(tv_name);
    
            btn_play = new Button(context);
            addView(btn_play);
            
            btn_delete = new Button(context);
            addView(btn_delete);
    	}
    	
    	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    		return inflater.inflate(R.layout.testfragment, container, false);
    	}
    }

Both `TestFragment` and `TestCustomView` can create a view consisting of `TextView` and `Buttons`, and use tags of `Framelayout/fragment` and `com.packagename.TestCustomView` to declare in the activity&#39;s xml layout file, but what&#39;s the advantages to use Fragment?

Fragment vs. Custom View in Android

When I include the below `XML` to *layout* file, I can see the below image. If you see it, you could realize that the `TextView` has top and bottom space. 

    &lt;TextView
    android:layout_width=&quot;wrap_content&quot;
    android:layout_height=&quot;wrap_content&quot;
    android:text=&quot;E1&quot;
    android:background=&quot;#ff00ff00&quot;/&gt;

![enter image description here][1]

I wish to remove the space. How to remove it? What is it called?
If anyone has clue.. please let me know. Thanks in advance.


  [1]: http://i.stack.imgur.com/zVjcH.gif

How to remove the top and bottom space on textview of Android

I get this warning (from the question title) in a custom Android view I am developing.

Why do I get warned? What&#39;s the logic behind it i.e. why is it a good  
practice to also override `performClick` when you override `onTouchEvent`?



Custom view ... overrides onTouchEvent but not performClick

In Android Studio, the layout editor cannot preview custom views in xml.

Very simple example:

    public class MyCustomView extends FrameLayout {
        public MyCustomView(Context context) {
            super(context);
        }

        public MyCustomView(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        public MyCustomView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
        }
    }

&amp;nbsp;

    &lt;LinearLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        android:orientation=&quot;horizontal&quot;&gt;

        &lt;com.myprojectxxx.view.MyCustomView
            android:layout_width=&quot;48dp&quot;
            android:layout_height=&quot;48dp&quot; /&gt;

    &lt;/LinearLayout&gt;

Android Studio always says,

&gt; Rendering Problems
&gt;
&gt; The following classes could not be found:
&gt;
&gt; - com.myprojectxxx.view.MyCustomView (Fix Build Path, Create Class)
&gt;
&gt; Tip: Try to build the project

Of course, I HAVE that class. If I click &quot;Create Class&quot;, it complains that the same class already exists. If I rebuild that project, nothing changes.

And, yes, the project works very well on my Android device. Also, it is rendered very well in Eclipse ADT. However, in Android Studio, it always says that &quot;CLASSES COULD NOT BE FOUND.&quot;

Android Studio does not have the ability to preview a xml file with custom views? What&#39;s wrong with this?

Android Studio layout editor cannot render custom views

I&#39;ve imported a project from Eclipse to Android studio. It utilizes a custom view:

    xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;

I get errors in the lines below from `activity_ro.xml` file like:

&gt; &quot;Error:(136) No resource identifier found for attribute
&gt; &#39;pstsTabPaddingLeftRight&#39; in package &#39;com.app.xxxx&#39;&quot;

    app:pstsDividerColor=&quot;#00000000&quot;
    app:pstsIndicatorColor=&quot;#FF33B5E6&quot;
    app:pstsTabPaddingLeftRight=&quot;14dip&quot;
    app:pstsUnderlineColor=&quot;#FF33B5E6&quot; /&gt;

I&#39;m not sure if custom views are different for gradle or maybe I&#39;m doing something wrong. Anyone have an idea? 

No resource identifier found for attribute &#39;...&#39; in package &#39;com.app....&#39;

I&#39;m calling the following in the constructor of my custom view:

    private void style(Resources.Theme theme, AttributeSet attrs) {
        TypedArray a = theme.obtainStyledAttributes(
                attrs,
                R.styleable.StackedTextView,
                0, 0);

        try {
            DebugTool.assertTrue(holdr != null, &quot;View holder has not been properly intialized.&quot;);
            String line1 = a.getString(R.styleable.StackedTextView_line1);
            setLine1(line1);
            String line2 = a.getString(R.styleable.StackedTextView_line2);
            setLine2(line2);

            line1Size = a.getDimension(R.styleable.StackedTextView_line1_textSize, 20);
            line2Size = a.getDimension(R.styleable.StackedTextView_line2_textSize, 20);
            if (line1Size &gt; 0) {
                holdr.textLine1.setTextSize(line1Size);
            }
            if (line2Size &gt; 0) {
                holdr.textLine2.setTextSize(line2Size);
            }

        } finally {
            a.recycle();
        }
    }

It&#39;s supposed to set text and text size for 2 textfields.

I have the following in my attr.xml in addition to the string formats for the text content (which works fine).

        &lt;attr name=&quot;line1_textSize&quot; format=&quot;dimension&quot; /&gt;
        &lt;attr name=&quot;line2_textSize&quot; format=&quot;dimension&quot; /&gt;

When I use this view and set the text size using a dimension via xml, 

            &lt;com.me.app.view.component.StackedTextView
                android:id=&quot;@+id/overview_total_reviews&quot;
                app:line1=&quot;40&quot;
                app:line2=&quot;Rating&quot;
                style=&quot;@style/OverviewStackedText&quot;
                app:line1_textSize=&quot;10sp&quot;
                app:line2_textSize=&quot;12sp&quot;
                /&gt;

the text ends up being significantly larger than expected. I&#39;m only setting 10 and 12sp respectively, and the text sizes are closer to like 30sp.

Can anyone see what I&#39;m doing wrong? Do I need to do something with DisplayMetrics to make sure things are scaled properly?

**Edit: Adding some clarification** 

The dimension IS getting picked up. The text does change when I set the different text sizes using my custom attribute (in xml). I&#39;ve also tried using `getDimensionPixelSize`.

It&#39;s as if the calculation/dimension retrieval is wrong. 1sp (or dp) change results in a significant change. 

Setting textSize in custom view results in huge text

I am building an Android application that uses the custom-built TwoDScrollView found here:

http://blog.gorges.us/2010/06/android-two-dimensional-scrollview/

This same class can be found referenced at several other websites, and others on Stack Overflow have asked questions with regard to it.  I was using it in a previous Android application that I was building using Java/Eclipse, and I was having success.

With my current application, I wanted to use C# and MonoDroid.  I decided to rewrite the entire TwoDScrollView class in C#.  After rewriting it, and then using it in some layout XML, I get the following exceptions when trying to run my code:

&gt; System.NotSupportedException has been thrown.  Unable to activate
&gt; instance of type MyProject.TwoDScrollView from native handle 44f4d310.
&gt; 
&gt; System.Exception: No constructor found for
&gt; MyProject.TwoDScrollView::.ctor(System.IntPtr,
&gt; Android.Runtime.JniHandleOwnership) ......with more text that
&gt; follows....

My layout XML is as follows:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;RelativeLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;	
        android:orientation=&quot;vertical&quot;
        android:layout_width=&quot;fill_parent&quot;
        android:layout_height=&quot;fill_parent&quot;
        &gt;
    	
    &lt;myproject.TwoDScrollView
    	android:layout_width=&quot;fill_parent&quot;
    	android:layout_height=&quot;fill_parent&quot;&gt;
    		
    &lt;/myproject.TwoDScrollView&gt;
    
    &lt;/RelativeLayout&gt;

Per the instructions at the following link on using custom views in layout XML in MonoDroid:  http://docs.xamarin.com/android/advanced_topics/using_custom_views_in_a_layout

The constructors to the TwoDScrollView class look as follows:

    public TwoDScrollView(Context context) 
    	: base(context)
    {
    	initTwoDScrollView();
    }
    
    public TwoDScrollView(Context context, IAttributeSet attrs) 
    	: base(context, attrs)
    {
    	initTwoDScrollView();
    }
    
    public TwoDScrollView(Context context, IAttributeSet attrs, int defStyle) 
    	: base(context, attrs, defStyle)
    {
    	initTwoDScrollView();
    }


The same constructors exist in the C# version as in the Java version (which you can find at the above link).  Any idea on what could be going wrong?  I can post the full C# code of my TwoDScrollView if anyone would like to see it.  It&#39;s essentially the same as the Java code bit for bit - except rewritten in C#.

Thanks for any help!

All Android Custom-View Solutions on Gang of Coders

Total of 15 Android Custom-View Solutions