I have two column of textView containing some text.
When you click in one text then click in another from other column it should draw a line between them.
I have put a relative layout between the two textView columns and adding a customised view to it.
I debugged and found that its calling the onDraw to draw line but i can not see any lines
Here is my code for that.
public class DrawLineView extends View {
Paint paint = new Paint();
View startView;
View endView;
public DrawLineView(Context context, View startView, View endView) {
super(context);
paint.setColor(Color.BLACK);
this.startView = startView;
this.endView = endView;
invalidate();
}
public DrawLineView(Context context) {
super(context);
}
// public void drawLineNow() {
//
// invalidate();
// }
#SuppressLint("NewApi")
public void onDraw(Canvas canvas) {
canvas.drawLine(startView.getX() + 25, startView.getY() + 50, endView.getX() + 25, endView.getY(), paint);
}
}
This is called in something like this.
selectedTextFromColumn2 = texviewC2T4;
selectedTag2 = list2.get(3).getTag();
if (selectedTag1 == selectedTag2) {
drawLineView = new DrawLineView(MatchingContentScreen.this,selectedTextFromColumn1, selectedTextFromColumn2);
relativeLayout.addView(drawLineView);
drawLineView.invalidate();
}
I am new to canvas .So i am confused what i am doing wrong or missing.
the line coming as a vertical line
I saw this drawing solution from another post.
How to draw a line in android between two or more RadioButtons
Can anyone please help me ?
I want it something like this
I can draw line like this if canvas is on top of these textviews
using
canvas.drawLine(startX , startY , stopX , stopY, paint);
but i can not validate the text or read the textview to match.
I have a layout, which has several views inside of it - toolbar, recyclerview and few separators (which are simple views with height of 2dp and match_parent width). I wanted to put a mask on a layout - most important part of it are the round corners for whole layout (and not the views itself). I decided to create my own LinearLayout class with overloaded dispatchDraw function and I managed to get nice result... except for one thing - those corners are not antialiased.
tl;dr is there ANY way to put antialias to clipPath function? I know can turn it on in Paint and then use xfermodes to mask the layout, however I have no clue how to draw mask and then draw everything else (without knowing what's exactly inside).
Here is my layout code (except for classname, simple constructors and Path field):
#Override protected void dispatchDraw(Canvas canvas) {
if (path == null) {
path = new Path();
float margin = MyApplication.getInstance().getMetrics().density * 5;
path.addRoundRect(new RectF(margin,margin,getWidth()-margin, getHeight()-margin),
margin*2, margin*2, Path.Direction.CW);
}
canvas.clipPath(path);
super.dispatchDraw(canvas);
}
#Override protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
}
try this SO answer, of course instead of mMask.draw(canvas) which is a "mask" made by a NinePatchDrawable you would need to call canvas.drawPath() with a Paint set with PorterDuff.Mode.DST_IN xfer mode
Let suppose we have the custom ListView which extends onDraw() method by drawing some rectangle in it.
class Listpicker extends ListView {
//..Some other methods here..//
#Override
protected void onDraw(android.graphics.Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(glassPickerBitmap, null, glassRect, semiTransparrentPaint);
}
}
The bitmap drawn represent some sort of glass which is rectangle with width equal to the width of listview and some height. What I want is when list item scrolls into this rectangle the color used for drawing text (not all item with background and etc.) would be changed into some another color. So, for example, when list item fits so that only half height of text fits into glassPickerBitmap, the outside part of list item should remain in its ordinal colors, and the part that is inside glassPickerBitmap should change its text color. List items are simple TextViews without any background.
How can be this achieved? Maybe any ColorFilters assigned to the Paint? But where? onDraw() method of Listview is not even called when ListView is scrolled... Can be this done inside customized views, for example, that will be ListView's items? Or may be some Color/Shader/do not know what else overlay can be used here, but where?
EDIT (added image examples):
Here is example of some crop from real-life app. There are 2 ListViews: one on the left side, other on the right. Glass is the grayed rectangle. Now, left list has "United States Dollar" currency selected. And I am scrolling right ListView in that way, that selection is somewhere between USD and Afghan Afghani. Now, what I want, is that USD currency in the left ListView would be drawn in red (exact color doesn't matter now, I will change it later to something meaningful) AND, in the same time, bottom part of "United States Dollar" and top part of "Afghan Afghani" in the right ListView would be drawn also in the same red color.
This color changing should be done in dynamic way - color should be changed only for the part of text that is under glass rectangle during scrolling of the list.
*OK, EUR and USD here are special currencies drawn with not standard cyan color. The question is about at least text with white color. But if it will be possible to change also cyan color it would be great.
As you can tell in their implementation they use and update a fixed position in their ListAdapter so then they update the View that matches accordingly, which is to me the easiest and simpler way to do it, but you don't get the half-half colored text, which I think you still want :)
So here is probably one of the worst answers I've given, sorry about it, I'll probably revisit this or hope someone can point you to a better solution
You can see a blurry demo at:
http://telly.com/Y98DS5
The dirty way:
Create a Paint with a proper ColorMatrixColorFilter, for the purposes of answering this I'm just desaturating, you'll have to figure out your 5x4 matrix for ColorMatrix to get the cyan your looking for. Also you will need some Rects to define source and dest when drawing below.
Create an off screen Bitmap and Canvas which you'll use to draw your list, that's done in onSizeChanged so we have proper view layout values, here you can start noticing the dirtiness as you will have to allocate a Bitmap as big as your ListView so you may get OutOfMemoryException.
Override draw to use your off screen Canvas and let ListView draw to it, then you can draw the Bitmap to the given Canvas that will draw your list as usual, then draw just the part of that Bitmap which will be drawn differently using the Paint we defined before, you will get overdraw for those pixels.
Finally draw your pre-fabricated glass Bitmap, I would recommend a n-patch (9-patch) so it scales and looks sharp across screens and densities, then you get more overdraw for those pixels.
The whole cake looks like:
public class OverlayView extends ListView {
private RectF mRect;
private Rect mSrcRect;
private Paint mPaint;
private Canvas mCanvas;
private Bitmap mBitmap;
private float mY;
private float mItemHeight;
public OverlayView(Context context) {
super(context);
initOverlay();
}
public OverlayView(Context context, AttributeSet attrs) {
super(context, attrs);
initOverlay();
}
public OverlayView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initOverlay();
}
private void initOverlay() {
// DO NOT DO THIS use attrs
final Resources res = getResources();
mY = res.getDimension(R.dimen.overlay_y);
mItemHeight = res.getDimension(R.dimen.item_height);
//
mRect = new RectF();
mSrcRect = new Rect();
mPaint = new Paint();
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.setSaturation(0);
mPaint.setColorFilter( new ColorMatrixColorFilter(colorMatrix) );
}
#Override
public void draw(Canvas canvas) {
super.draw(mCanvas);
canvas.drawBitmap(mBitmap, 0, 0, null);
canvas.drawBitmap(mBitmap, mSrcRect, mRect, mPaint);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mRect.set(0, mY, w, mY + mItemHeight);
mRect.roundOut(mSrcRect);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
}
So that said, I hope you end up with a cleaner solution, even if you don't get that half-half sexiness :)
First, keep a spare bitmap and canvas:
class Listpicker extends ListView {
Bitmap bitmapForOnDraw = null;
Canvas canvasForOnDraw = null;
Make sure it's the right size:
#override
protected void onSizeChanged (int w, int h, int oldw, int oldh) {
if (bitmapForOnDraw != null) bitmapForOnDraw.recycle();
bitmapForOnDraw = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
canvasForOnDraw = new Canvas(bitmapForOnDraw);
}
And when we come to drawing the list:
#override
protected void onDraw(android.graphics.Canvas realCanvas) {
// Put the list in place
super.onDraw(realCanvas);
// Now get the same again
canvasForOnDraw.drawColor(0x00000000, PorterDuff.Mode.CLEAR);
super.onDraw(canvasForOnDraw);
// But now change the colour of the white text
canvasForOnDraw.drawColor(0xffff00ff, PorterDuff.Mode.MULTIPLY);
// Copy the different colour text into the right place
canvas.drawBitmap(bitmapForOnDraw, glassRect, glassRect overwritePaint);
// finally, put the box on.
canvas.drawBitmap(glassPickerBitmap, null, glassRect, semiTransparrentPaint);
}
I created a drawing using different paths, but how can I move the entire drawing? How can I selected and move it around? Here is the main part of my onDraw method:
Path theSymbol = new Path();
theSymbol.moveTo(0.0F, 0.0F);
theSymbol.lineTo(0.0F, 50.0F);
theSymbol.lineTo(16.666666F, 58.333332F);
theSymbol.lineTo(-16.666666F, 75.0F);
theSymbol.lineTo(16.666666F, 91.666664F);
theSymbol.lineTo(-16.666666F, 108.33333F);
theSymbol.lineTo(16.666666F, 124.99999F);
theSymbol.lineTo(-16.666666F, 141.66666F);
theSymbol.lineTo(0.0F, 150.0F);
theSymbol.lineTo(0.0F, 200.0F);
theSymbol.offset(100.0F, 20.0F);
canvas.drawPath(theSymbol, paint);
That's how I draw a resistor to the screen (It works). Now I want some way of making all those paths be an object, something that I can select and move.
I have been looking at some projects like Sriracha, but I can't find how they are doing their element drawings.
I have also searched countless times, but all I get is "moving something on a path". Maibe I am searching for the wrong thing or this is not the way to do this kind of things.
I wold really appreciate if someone can point me in the right direction.
Put this drawing code into the onDraw() method of a custom View subclass. Then you can place your drawings around the screen however you like using layouts, animations, and other transformations just like any other view in the framework. Something like:
public class ResistorView extends View {
private Path mSymbol;
private Paint mPaint;
//...Override Constructors...
public ResistorView(Context context) {
super(context);
init();
}
public ResistorView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
mSymbol = new Path();
mPaint = new Paint();
//...Your code here to set up the path,
//...allocate objects here, never in the drawing code.
}
//...Override onMeasure()...
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//Use this method to tell Android how big your view is
setMeasuredDimension(width, height);
}
//...Override onDraw()...
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawPath(mSymbol, mPaint);
}
}
For more information about creating custom views, check out the SDK docs.
HTH
I need some help to make an activity.
I have stored coordinates from shapes and name of shapes in a database. These are grouped into rooms.
In the activity I need the top of the screen 8 TextViews (with colors and textst) in two rows. If I click on a textView, accordingly the shapes for the room need to be drawn on the screen under the textViews.
If I click on a shape, I need to get back the information, on which shape I made a click.
I guess you could create a custom view:
public class CustomView extends View { ... }
and then you simply override appropriate methods like:
#Override
public boolean onTouchEvent(MotionEvent ev) { /* check for hitting shapes here */ }
#Override
protected void onDraw(Canvas canvas) { /* draw anything you want here */ }
Use the search engine of your choice to find out more. This looks like what you need