w1c*_*d64 29 android drag-and-drop zoom pinch imageview
我目前正在为Android(我的第一个应用程序)开发一个应用程序,它可以让用户看到地铁地图,并能够捏缩放和拖动.
我目前正在修改Hello Android,3rd Edition中的代码,并进行了缩放缩放和拖动工作.我正在使用Matrix作为我的布局比例.
但是我现在有3个问题:
我尝试了很多东西来限制拖动参数,但我似乎无法阻止它被拖离父视图(并且实际上可以从视图中消失).我已经尝试在XML文件中设置布局参数,但它不起作用.
我可以捏缩放,但我又遇到了麻烦,限制了变焦量.我正在尝试设置max_zoom和min_zoom以限制缩放值(我将在之后发布我的代码)
我也很难尝试在我的图像上映射坐标,以便人们可以点击某些部分(这一点的全部意义是让用户点击地图上的一个工作站并查看有关它的信息)
我有一种感觉我遇到了麻烦,因为我正在使用矩阵比例.
这是我目前的代码:
Touch.java
package org.example.touch;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.GridView;
import android.widget.ImageView;
public class Touch extends Activity implements OnTouchListener {
private static final String TAG = "Touch";
private static final float MIN_ZOOM = 1.0f;
private static final float MAX_ZOOM = 5.0f;
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView view = (ImageView) findViewById(R.id.imageView);
//view.setLayoutParams(new GridView.LayoutParams(85, 85));
view.setScaleType(ImageView.ScaleType.FIT_CENTER);
view.setOnTouchListener(this);
}
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
float scale;
// Dump touch event to log
dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: //first finger down only
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG" );
mode = DRAG;
break;
case MotionEvent.ACTION_UP: //first finger lifted
case MotionEvent.ACTION_POINTER_UP: //second finger lifted
mode = NONE;
Log.d(TAG, "mode=NONE" );
break;
case MotionEvent.ACTION_POINTER_DOWN: //second finger down
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 5f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM" );
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) { //movement of first finger
matrix.set(savedMatrix);
if (view.getLeft() >= -392){
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);
}
}
else if (mode == ZOOM) { //pinch zooming
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 5f) {
matrix.set(savedMatrix);
scale = newDist / oldDist; **//thinking i need to play around with this value to limit it**
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
// Perform the transformation
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event) {
String names[] = { "DOWN" , "UP" , "MOVE" , "CANCEL" , "OUTSIDE" ,
"POINTER_DOWN" , "POINTER_UP" , "7?" , "8?" , "9?" };
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_" ).append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN
|| actionCode == MotionEvent.ACTION_POINTER_UP) {
sb.append("(pid " ).append(
action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")" );
}
sb.append("[" );
for (int i = 0; i < event.getPointerCount(); i++) {
sb.append("#" ).append(i);
sb.append("(pid " ).append(event.getPointerId(i));
sb.append(")=" ).append((int) event.getX(i));
sb.append("," ).append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";" );
}
sb.append("]" );
Log.d(TAG, sb.toString());
}
}
main.xml(相当简单,没有什么真正复杂):
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ImageView android:id="@+id/imageView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/map"
android:scaleType="matrix" >
</ImageView>
</FrameLayout>
AndroidManifest.xml(仅添加了主题,因此没有标题栏并且是全屏)
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="org.example.touch"
android:versionCode="7"
android:versionName="1.0" >
<application android:icon="@drawable/icon" android:label="@string/app_name" android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >
<activity android:name=".Touch"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-sdk android:minSdkVersion="3" android:targetSdkVersion="7" />
</manifest>
Jas*_*tes 18
我刚刚创建了这个:
https://github.com/jasonpolites/gesture-imageview
可能对某人有用......
Ern*_*son 12
另一个可能适用于某些选项的选项是使用WebView内置缩放控件的a.
WebView webView = new WebView(this);
webView.setBackgroundColor(0xff000000);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
webView.getSettings().setBuiltInZoomControls(true);
webView.getSettings().setSupportZoom(true);
//webView.getSettings().setDisplayZoomControls(false); // API 11
webView.loadDataWithBaseURL(null, getHtml(), "text/html", "UTF-8", null);
mainView.addView(webView, -1, -2);
我知道这已经过时了,但我正在考虑做这个并且有一个非常好的解决方案.在切换语句之后和设置矩阵之前,您可以限制缩放,如下所示:
private void limitZoom(Matrix m) {
float[] values = new float[9];
m.getValues(values);
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
if(scaleX > MAX_ZOOM) {
scaleX = MAX_ZOOM;
} else if(scaleX < MIN_ZOOM) {
scaleX = MIN_ZOOM;
}
if(scaleY > MAX_ZOOM) {
scaleY = MAX_ZOOM;
} else if(scaleY < MIN_ZOOM) {
scaleY = MIN_ZOOM;
}
values[Matrix.MSCALE_X] = scaleX;
values[Matrix.MSCALE_Y] = scaleY;
m.setValues(values);
}
我还在研究如何限制翻译,但这应该适用于缩放限制.
编辑:这是限制翻译的解决方案.就像一个注释,我这样做是为了全屏图像视图,这就是为什么我在限制因素中使用显示宽度和高度,但你可以轻松地使用视图的宽度和高度.
private void limitDrag(Matrix m) {
float[] values = new float[9];
m.getValues(values);
float transX = values[Matrix.MTRANS_X];
float transY = values[Matrix.MTRANS_Y];
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
ImageView iv = (ImageView)findViewById(R.id.photo_view);
Rect bounds = iv.getDrawable().getBounds();
int viewWidth = getResources().getDisplayMetrics().widthPixels;
int viewHeight = getResources().getDisplayMetrics().heightPixels;
int width = bounds.right - bounds.left;
int height = bounds.bottom - bounds.top;
float minX = (-width + 20) * scaleX;
float minY = (-height + 20) * scaleY;
if(transX > (viewWidth - 20)) {
transX = viewWidth - 20;
} else if(transX < minX) {
transX = minX;
}
if(transY > (viewHeight - 80)) {
transY = viewHeight - 80;
} else if(transY < minY) {
transY = minY;
}
values[Matrix.MTRANS_X] = transX;
values[Matrix.MTRANS_Y] = transY;
m.setValues(values);
}
再次,这将在您的switch语句之后,在您在视图中设置图像的矩阵之前.我也将缩放限制分解成了一个函数,它反映在上面.
这是捏缩放和平移的完整代码(Touch.java带有一些可以实际使用的修改)
public class Touch implements OnTouchListener {
// These matrices will be used to move and zoom image
public static Matrix matrix = new Matrix();
public static Matrix savedMatrix = new Matrix();
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
private static final float MAX_ZOOM = (float) 3;
private static final float MIN_ZOOM = 1;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
int width,height;
@Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
Rect bounds = view.getDrawable().getBounds();
width = bounds.right - bounds.left;
height = bounds.bottom - bounds.top;
// Dump touch event to log
dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
// ...
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
//----------------------------------------------------
limitZoom(matrix);
limitDrag( matrix);
//----------------------------------------------------
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event) {
String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
"POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_").append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN
|| actionCode == MotionEvent.ACTION_POINTER_UP) {
sb.append("(pid ").append(
action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")");
}
sb.append("[");
for (int i = 0; i < event.getPointerCount(); i++) {
sb.append("#").append(i);
sb.append("(pid ").append(event.getPointerId(i));
sb.append(")=").append((int) event.getX(i));
sb.append(",").append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";");
}
sb.append("]");
}
/** Determine the space between the first two fingers */
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
/** Calculate the mid point of the first two fingers */
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
private void limitZoom(Matrix m) {
float[] values = new float[9];
m.getValues(values);
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
if(scaleX > MAX_ZOOM) {
scaleX = MAX_ZOOM;
} else if(scaleX < MIN_ZOOM) {
scaleX = MIN_ZOOM;
}
if(scaleY > MAX_ZOOM) {
scaleY = MAX_ZOOM;
} else if(scaleY < MIN_ZOOM) {
scaleY = MIN_ZOOM;
}
values[Matrix.MSCALE_X] = scaleX;
values[Matrix.MSCALE_Y] = scaleY;
m.setValues(values);
}
private void limitDrag(Matrix m) {
float[] values = new float[9];
m.getValues(values);
float transX = values[Matrix.MTRANS_X];
float transY = values[Matrix.MTRANS_Y];
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
//--- limit moving to left ---
float minX = (-width + 0) * (scaleX-1);
float minY = (-height + 0) * (scaleY-1);
//--- limit moving to right ---
float maxX=minX+width*(scaleX-1);
float maxY=minY+height*(scaleY-1);
if(transX>maxX){transX = maxX;}
if(transX<minX){transX = minX;}
if(transY>maxY){transY = maxY;}
if(transY<minY){transY = minY;}
values[Matrix.MTRANS_X] = transX;
values[Matrix.MTRANS_Y] = transY;
m.setValues(values);
}
}
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