zooming EditText without losing quality?

Question

I'm using a code for zooming my EditText and it works 100%, but the problem is when zooming the text losses its quality like zooming an image.

I need it to zoom the font in the text like making it's size bigger (size up)

---

This is my code for xml:

<ScrollView
    android:layout_width="fill_parent"
    android:layout_height="250dp"
    android:visibility="invisible"
    android:background="@null"
    android:id="@+id/SResult">
    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="250dp">
        <TextView
            android:layout_width="fill_parent"
            android:layout_height="1000dp"
            android:visibility="invisible"

            android:id="@+id/backtxt"
            android:background="@android:color/white"
            />

        <com.calcupital.calcupital.ZoomView
            android:id="@+id/zoomView3"
            android:layout_width="fill_parent"
            android:layout_height="1000dp"
            >

            <EditText
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:id="@+id/Result"
                android:gravity="left"
                android:padding="5dp"
                android:visibility="invisible"
                android:textSize="16dp"
                android:textColor="@android:color/black"
                android:background="@null"
                android:inputType="none" />
        </com.calcupital.calcupital.ZoomView>

    </RelativeLayout>
</ScrollView>

and java:

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.FrameLayout;


public class ZoomView extends FrameLayout {

public ZoomView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    // TODO Auto-generated constructor stub
}

public ZoomView(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub
}

public ZoomView(final Context context) {
    super(context);
}

/**
 * Zooming view listener interface.
 *
 * @author karooolek
 *
 */
public interface ZoomViewListener {

    void onZoomStarted(float zoom, float zoomx, float zoomy);

    void onZooming(float zoom, float zoomx, float zoomy);

    void onZoomEnded(float zoom, float zoomx, float zoomy);
}

// zooming
float zoom = 1.0f;
float maxZoom = 2.0f;
float smoothZoom = 1.0f;
float zoomX, zoomY;
float smoothZoomX, smoothZoomY;
private boolean scrolling; // NOPMD by karooolek on 29.06.11 11:45

// minimap variables
private boolean showMinimap = false;
private int miniMapColor = Color.WHITE;
private int miniMapHeight = -1;
private String miniMapCaption;
private float miniMapCaptionSize = 10.0f;
private int miniMapCaptionColor = Color.WHITE;

// touching variables
private long lastTapTime;
private float touchStartX, touchStartY;
private float touchLastX, touchLastY;
private float startd;
private boolean pinching;
private float lastd;
private float lastdx1, lastdy1;
private float lastdx2, lastdy2;

// drawing
private final Matrix m = new Matrix();
private final Paint p = new Paint();

// listener
ZoomViewListener listener;

private Bitmap ch;

public float getZoom() {
    return zoom;
}

public float getMaxZoom() {
    return maxZoom;
}

public void setMaxZoom(final float maxZoom) {
    if (maxZoom < 1.0f) {
        return;
    }

    this.maxZoom = maxZoom;
}

public void setMiniMapEnabled(final boolean showMiniMap) {
    this.showMinimap = showMiniMap;
}

public boolean isMiniMapEnabled() {
    return showMinimap;
}

public void setMiniMapHeight(final int miniMapHeight) {
    if (miniMapHeight < 0) {
        return;
    }
    this.miniMapHeight = miniMapHeight;
}

public int getMiniMapHeight() {
    return miniMapHeight;
}

public void setMiniMapColor(final int color) {
    miniMapColor = color;
}

public int getMiniMapColor() {
    return miniMapColor;
}

public String getMiniMapCaption() {
    return miniMapCaption;
}

public void setMiniMapCaption(final String miniMapCaption) {
    this.miniMapCaption = miniMapCaption;
}

public float getMiniMapCaptionSize() {
    return miniMapCaptionSize;
}

public void setMiniMapCaptionSize(final float size) {
    miniMapCaptionSize = size;
}

public int getMiniMapCaptionColor() {
    return miniMapCaptionColor;
}

public void setMiniMapCaptionColor(final int color) {
    miniMapCaptionColor = color;
}

public void zoomTo(final float zoom, final float x, final float y) {
    this.zoom = Math.min(zoom, maxZoom);
    zoomX = x;
    zoomY = y;
    smoothZoomTo(this.zoom, x, y);
}

public void smoothZoomTo(final float zoom, final float x, final float y) {
    smoothZoom = clamp(1.0f, zoom, maxZoom);
    smoothZoomX = x;
    smoothZoomY = y;
    if (listener != null) {
        listener.onZoomStarted(smoothZoom, x, y);
    }
}

public ZoomViewListener getListener() {
    return listener;
}

public void setListner(final ZoomViewListener listener) {
    this.listener = listener;
}

public float getZoomFocusX() {
    return zoomX * zoom;
}

public float getZoomFocusY() {
    return zoomY * zoom;
}

@Override
public boolean dispatchTouchEvent(final MotionEvent ev) {
    // single touch
    if (ev.getPointerCount() == 1) {
        processSingleTouchEvent(ev);
    }

    // // double touch
    if (ev.getPointerCount() == 2) {
        processDoubleTouchEvent(ev);
    }

    // redraw
    getRootView().invalidate();
    invalidate();

    return true;
}

private void processSingleTouchEvent(final MotionEvent ev) {

    final float x = ev.getX();
    final float y = ev.getY();

    final float w = miniMapHeight * (float) getWidth() / getHeight();
    final float h = miniMapHeight;
    final boolean touchingMiniMap = x >= 10.0f && x <= 10.0f + w
            && y >= 10.0f && y <= 10.0f + h;

    if (showMinimap && smoothZoom > 1.0f && touchingMiniMap) {
        processSingleTouchOnMinimap(ev);
    } else {
        processSingleTouchOutsideMinimap(ev);
    }
}

private void processSingleTouchOnMinimap(final MotionEvent ev) {
    final float x = ev.getX();
    final float y = ev.getY();

    final float w = miniMapHeight * (float) getWidth() / getHeight();
    final float h = miniMapHeight;
    final float zx = (x - 10.0f) / w * getWidth();
    final float zy = (y - 10.0f) / h * getHeight();
    smoothZoomTo(smoothZoom, zx, zy);
}

private void processSingleTouchOutsideMinimap(final MotionEvent ev) {
    final float x = ev.getX();
    final float y = ev.getY();
    float lx = x - touchStartX;
    float ly = y - touchStartY;
    final float l = (float) Math.hypot(lx, ly);
    float dx = x - touchLastX;
    float dy = y - touchLastY;
    touchLastX = x;
    touchLastY = y;

    switch (ev.getAction()) {
        case MotionEvent.ACTION_DOWN:
            touchStartX = x;
            touchStartY = y;
            touchLastX = x;
            touchLastY = y;
            dx = 0;
            dy = 0;
            lx = 0;
            ly = 0;
            scrolling = false;
            break;

        case MotionEvent.ACTION_MOVE:
            if (scrolling || (smoothZoom > 1.0f && l > 30.0f)) {
                if (!scrolling) {
                    scrolling = true;
                    ev.setAction(MotionEvent.ACTION_CANCEL);
                    super.dispatchTouchEvent(ev);
                }
                smoothZoomX -= dx / zoom;
                smoothZoomY -= dy / zoom;
                return;
            }
            break;

        case MotionEvent.ACTION_OUTSIDE:
        case MotionEvent.ACTION_UP:

            // tap
            if (l < 30.0f) {
                // check double tap
                if (System.currentTimeMillis() - lastTapTime < 500) {
                    if (smoothZoom == 1.0f) {
                        smoothZoomTo(maxZoom, x, y);
                    } else {
                        smoothZoomTo(1.0f, getWidth() / 2.0f,
                                getHeight() / 2.0f);
                    }
                    lastTapTime = 0;
                    ev.setAction(MotionEvent.ACTION_CANCEL);
                    super.dispatchTouchEvent(ev);
                    return;
                }

                lastTapTime = System.currentTimeMillis();

                performClick();
            }
            break;

        default:
            break;
    }

    ev.setLocation(zoomX + (x - 0.5f * getWidth()) / zoom, zoomY
            + (y - 0.5f * getHeight()) / zoom);

    ev.getX();
    ev.getY();

    super.dispatchTouchEvent(ev);
}

private void processDoubleTouchEvent(final MotionEvent ev) {
    final float x1 = ev.getX(0);
    final float dx1 = x1 - lastdx1;
    lastdx1 = x1;
    final float y1 = ev.getY(0);
    final float dy1 = y1 - lastdy1;
    lastdy1 = y1;
    final float x2 = ev.getX(1);
    final float dx2 = x2 - lastdx2;
    lastdx2 = x2;
    final float y2 = ev.getY(1);
    final float dy2 = y2 - lastdy2;
    lastdy2 = y2;

    // pointers distance
    final float d = (float) Math.hypot(x2 - x1, y2 - y1);
    final float dd = d - lastd;
    lastd = d;
    final float ld = Math.abs(d - startd);

    Math.atan2(y2 - y1, x2 - x1);
    switch (ev.getAction()) {
        case MotionEvent.ACTION_DOWN:
            startd = d;
            pinching = false;
            break;

        case MotionEvent.ACTION_MOVE:
            if (pinching || ld > 30.0f) {
                pinching = true;
                final float dxk = 0.5f * (dx1 + dx2);
                final float dyk = 0.5f * (dy1 + dy2);
                smoothZoomTo(Math.max(1.0f, zoom * d / (d - dd)), zoomX -    dxk
                        / zoom, zoomY - dyk / zoom);
            }

            break;

        case MotionEvent.ACTION_UP:
        default:
            pinching = false;
            break;
    }

    ev.setAction(MotionEvent.ACTION_CANCEL);
    super.dispatchTouchEvent(ev);
}

private float clamp(final float min, final float value, final float max)   {
    return Math.max(min, Math.min(value, max));
}

private float lerp(final float a, final float b, final float k) {
    return a + (b - a) * k;
}

private float bias(final float a, final float b, final float k) {
    return Math.abs(b - a) >= k ? a + k * Math.signum(b - a) : b;
}

@Override
protected void dispatchDraw(final Canvas canvas) {

    // do zoom
    zoom = lerp(bias(zoom, smoothZoom, 0.05f), smoothZoom, 0.2f);
    smoothZoomX = clamp(0.5f * getWidth() / smoothZoom, smoothZoomX,
            getWidth() - 0.5f * getWidth() / smoothZoom);
    smoothZoomY = clamp(0.5f * getHeight() / smoothZoom, smoothZoomY,
            getHeight() - 0.5f * getHeight() / smoothZoom);

    zoomX = lerp(bias(zoomX, smoothZoomX, 0.1f), smoothZoomX, 0.35f);
    zoomY = lerp(bias(zoomY, smoothZoomY, 0.1f), smoothZoomY, 0.35f);
    if (zoom != smoothZoom && listener != null) {
        listener.onZooming(zoom, zoomX, zoomY);
    }

    final boolean animating = Math.abs(zoom - smoothZoom) > 0.0000001f
            || Math.abs(zoomX - smoothZoomX) > 0.0000001f
            || Math.abs(zoomY - smoothZoomY) > 0.0000001f;

    // nothing to draw
    if (getChildCount() == 0) {
        return;
    }

    // prepare matrix
    m.setTranslate(0.5f * getWidth(), 0.5f * getHeight());
    m.preScale(zoom, zoom);
    m.preTranslate(
            -clamp(0.5f * getWidth() / zoom, zoomX, getWidth() - 0.5f
                    * getWidth() / zoom),
            -clamp(0.5f * getHeight() / zoom, zoomY, getHeight() - 0.5f
                    * getHeight() / zoom));

    // get view
    final View v = getChildAt(0);
    m.preTranslate(v.getLeft(), v.getTop());

    // get drawing cache if available
    if (animating && ch == null && isAnimationCacheEnabled()) {
        v.setDrawingCacheEnabled(true);
        ch = v.getDrawingCache();
    }

    // draw using cache while animating
    if (animating && isAnimationCacheEnabled() && ch != null) {
        p.setColor(0xffffffff);
        canvas.drawBitmap(ch, m, p);
    } else { // zoomed or cache unavailable
        ch = null;
        canvas.save();
        canvas.concat(m);
        v.draw(canvas);
        canvas.restore();
    }

    // draw minimap
    if (showMinimap) {
        if (miniMapHeight < 0) {
            miniMapHeight = getHeight() / 4;
        }

        canvas.translate(10.0f, 10.0f);

        p.setColor(0x80000000 | 0x00ffffff & miniMapColor);
        final float w = miniMapHeight * (float) getWidth() / getHeight();
        final float h = miniMapHeight;
        canvas.drawRect(0.0f, 0.0f, w, h, p);

        if (miniMapCaption != null && miniMapCaption.length() > 0) {
            p.setTextSize(miniMapCaptionSize);
            p.setColor(miniMapCaptionColor);
            p.setAntiAlias(true);
            canvas.drawText(miniMapCaption, 10.0f,
                    10.0f + miniMapCaptionSize, p);
            p.setAntiAlias(false);
        }

        p.setColor(0x80000000 | 0x00ffffff & miniMapColor);
        final float dx = w * zoomX / getWidth();
        final float dy = h * zoomY / getHeight();
        canvas.drawRect(dx - 0.5f * w / zoom, dy - 0.5f * h / zoom, dx
                + 0.5f * w / zoom, dy + 0.5f * h / zoom, p);

        canvas.translate(-10.0f, -10.0f);
    }

    // redraw
    // if (animating) {
    getRootView().invalidate();
    invalidate();
    // }
 }
}

and this is my java code for main activity:

final static float STEP = 200;
TextView mtxtRatio1, mtxtRatio2, mtxtRatio3, mtxtRatio4;
float mRatio = 1.0f;
int mBaseDist;
float mBaseRatio;
float fontsize = 13;

So, how can I resolve this issue and make zooming for the text without loosing the quality?

Answer 1

set a custom selector as background for your EditText with only colors (noImage). It "MAY" work, i didn't tested it.tell me if it works

EDIT:2

View

<Button
        android:id="@+id/bButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/bookbutton_selector"
        android:text="Button" />

drawables/bookbutton_selector

<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:state_pressed="false" android:drawable="@drawable/bookbutton_normal"/>
    <item android:state_pressed="true" android:drawable="@drawable/bookbutton_pressed"/>
</selector>

drawables/bookbutton_normal

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <corners android:radius="5dp" />

    <gradient 
        android:startColor="@color/bookmany"
        android:endColor="@color/bookmany_dark"
        />


</shape>

drawables/bookbutton_pressed

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <corners android:radius="5dp" />

    <gradient
        android:endColor="#333"
        android:startColor="#333" />

</shape>

This is a case of button, and this is also applicable for EditText with small changes in selector.

As you can see i set the selector as the background for the Button, this will help you the button to have custom style when get Clicked and Released.

Try it out. Let me know if you need more help