java - 缩放 EditText 而不损失质量？

Question

我正在使用代码来缩放 EditText，它可以 100% 工作，但问题是缩放文本时会像缩放图像一样失去其质量。

我需要它来缩放文本中的字体，例如使其尺寸更大(放大)

<小时/>

这是我的 xml 代码:

<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>

和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();
    // }
 }
}

这是我主要 Activity 的 java 代码:

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

那么，如何解决这个问题并在不损失质量的情况下缩放文本？

Answer 1

将自定义选择器设置为仅包含颜色的 EditText 背景(noImage)。它“可能”有效，我没有测试它。告诉我它是否有效

编辑:2

查看

<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>

这是按钮的情况，这也适用于选择器稍作改动的EditText。

正如您所看到的，我将选择器设置为按钮的背景，这将帮助您在单击并释放时使按钮具有自定义样式。

尝试一下。如果您需要更多帮助，请告诉我