Any Component can have a MouseListener. JLabel is nice for a colored rectangle, as long as you make it opaque. Addendum: Having recommended MouseAdapter elsewhere, I should mention that one instance is enough. Addendum: This update adds the mouse listener in the ColorLabel constructor. import java.awt.Color; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.GridLayout; import java.awt.event.MouseAdapter; import … Read more
You can use an AnimationController to control the animation duration. To draw the line “step by step” you can use a Tween (linear interpolation between a beginning and ending value). Then you just need to pass the current progress to your line painter and calculate the new width/height on each paint() when you call canvas.drawLine. … Read more
Your class should implement ColorPickerDialog.OnColorChangedListener public class MainActivity implements ColorPickerDialog.OnColorChangedListener { private Paint mPaint; mPaint = new Paint(); // on button click new ColorPickerDialog(this, this, mPaint.getColor()).show(); } ColorPicker Dialog public class ColorPickerDialog extends Dialog { public interface OnColorChangedListener { void colorChanged(int color); } private OnColorChangedListener mListener; private int mInitialColor; private static class ColorPickerView extends View … Read more
One of the reasons the paintComponent() doesn’t get invoked in the original code is because the component has a “zero size” and the RepaintManger is smart enough not to try and paint something with no size. The reason the reordering of the code works is because when you add the component to the frame and … Read more
Don’t use paint, use paintComponent and don’t forget to call super.paintComponent JComponent may not be the best choice, JPanel is probably a better choice What’s wrong with Graphics#fillRect(int, int, int, int)? You might to take a look at Performing Custom Painting and 2D Graphics for more details. I’d advice against trying to have a second … Read more
You need to get the densityMultiplier like so: final float densityMultiplier = getContext().getResources().getDisplayMetrics().density; final float scaledPx = 20 * densityMultiplier; paint.setTextSize(scaledPx); final float size = paint.measureText(“sample text”);
You should override paintComponent in your JPanel and call super.paintComponent(g) in it. See How to Use Key Bindings tutorial. Key bindings are preffered in this case rather than a KeyListener pack() then setVisible() You should set global variables for x anf y location, so they can be accessed from within your Action. Then in your … Read more
setShadowLayer() is only supported on text when hardware acceleration is on. Hardware acceleration is on by default when targetSdk=14 or higher. An easy workaround is to put your View in a software layer: myView.setLayerType(View.LAYER_TYPE_SOFTWARE, null).
You are using exact color fill for dithered/smoothed/antialiased/lossy_compressed image. That leaves pixels with even slightly different color uncolored (borders) creating artifacts. There are 2 easy ways how to remedy it: match close colors instead of exact if you got 2 RGB colors (r0,g0,b0) and (r1,g1,b1) right now (if I see it right) your checking is … Read more
As you found, a BufferedImage is an effective way to cache complex content for efficient rendering; CellTest is an example. A flyweight renderer, shown here, is another approach. Finally, I’ve re-factored your instructive example in a way that may make experimentation easier. import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import … Read more