Android开源库--PhotoView图片查看

如果说我比别人看得更远些,那是因为我站在了巨人的肩上。

github地址：https://github.com/chrisbanes/PhotoView

介绍

在一般的应用中，总会遇到查看图片的功能，点击图片之后，详细查看，PhotoView这个开源控件就帮我们很好的完成了这个功能。

它继承自ImageView，支持缩放，以及各种手势的监听。

特性

• 通过多点触摸和双击来进行放大。
• 通过轻弹划实现平滑滚动。
• 在带有滚动功能的父类工作的很好（比如ViewPager）
• 允许当显示的矩阵发生发生改变时通知应用，当你需要基于当前缩放/滑动位置来更新你的ui时非常有用。
• 允许当你点击图片时通知应用

使用

1、通过代码附加ImageView使用

ImageView mImageView;
PhotoViewAttacher mAttacher;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Any implementation of ImageView can be used!
    mImageView = (ImageView) findViewById(R.id.iv_photo);

    // Set the Drawable displayed
    Drawable bitmap = getResources().getDrawable(R.drawable.wallpaper);
    mImageView.setImageDrawable(bitmap);

    // Attach a PhotoViewAttacher, which takes care of all of the zooming functionality.
    mAttacher = new PhotoViewAttacher(mImageView);
}


// If you later call mImageView.setImageDrawable/setImageBitmap/setImageResource/etc then you just need to call
attacher.update();

2、通过layout使用。

<uk.co.senab.photoview.PhotoView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/iv_photo"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"/>

PS：如果需要旋转图片可以通过setRotationTo，setRotationBy实现，其他相关操作间示例代码：

/*******************************************************************************
 * Copyright 2011, 2012 Chris Banes.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package uk.co.senab.photoview.sample;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.TextView;
import android.widget.Toast;

import java.io.File;
import java.io.FileOutputStream;
import java.util.Random;

import uk.co.senab.photoview.PhotoViewAttacher;
import uk.co.senab.photoview.PhotoViewAttacher.OnMatrixChangedListener;
import uk.co.senab.photoview.PhotoViewAttacher.OnPhotoTapListener;

public class SimpleSampleActivity extends Activity {

    static final String PHOTO_TAP_TOAST_STRING = "Photo Tap! X: %.2f %% Y:%.2f %% ID: %d";
    static final String SCALE_TOAST_STRING = "Scaled to: %.2ff";

    private TextView mCurrMatrixTv;

    private PhotoViewAttacher mAttacher;

    private Toast mCurrentToast;

    private Matrix mCurrentDisplayMatrix = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ImageView mImageView = (ImageView) findViewById(R.id.iv_photo);
        mCurrMatrixTv = (TextView) findViewById(R.id.tv_current_matrix);

        Drawable bitmap = getResources().getDrawable(R.drawable.wallpaper);
        mImageView.setImageDrawable(bitmap);

        // The MAGIC happens here!
        mAttacher = new PhotoViewAttacher(mImageView);

        // Lets attach some listeners, not required though!
        mAttacher.setOnMatrixChangeListener(new MatrixChangeListener());
        mAttacher.setOnPhotoTapListener(new PhotoTapListener());
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();

        // Need to call clean-up
        mAttacher.cleanup();
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        MenuItem zoomToggle = menu.findItem(R.id.menu_zoom_toggle);
        assert null != zoomToggle;
        zoomToggle.setTitle(mAttacher.canZoom() ? R.string.menu_zoom_disable : R.string.menu_zoom_enable);

        return super.onPrepareOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_zoom_toggle:
                mAttacher.setZoomable(!mAttacher.canZoom());
                return true;

            case R.id.menu_scale_fit_center:
                mAttacher.setScaleType(ScaleType.FIT_CENTER);
                return true;

            case R.id.menu_scale_fit_start:
                mAttacher.setScaleType(ScaleType.FIT_START);
                return true;

            case R.id.menu_scale_fit_end:
                mAttacher.setScaleType(ScaleType.FIT_END);
                return true;

            case R.id.menu_scale_fit_xy:
                mAttacher.setScaleType(ScaleType.FIT_XY);
                return true;

            case R.id.menu_scale_scale_center:
                mAttacher.setScaleType(ScaleType.CENTER);
                return true;

            case R.id.menu_scale_scale_center_crop:
                mAttacher.setScaleType(ScaleType.CENTER_CROP);
                return true;

            case R.id.menu_scale_scale_center_inside:
                mAttacher.setScaleType(ScaleType.CENTER_INSIDE);
                return true;

            case R.id.menu_scale_random_animate:
            case R.id.menu_scale_random:
                Random r = new Random();

                float minScale = mAttacher.getMinimumScale();
                float maxScale = mAttacher.getMaximumScale();
                float randomScale = minScale + (r.nextFloat() * (maxScale - minScale));
                mAttacher.setScale(randomScale, item.getItemId() == R.id.menu_scale_random_animate);

                showToast(String.format(SCALE_TOAST_STRING, randomScale));

                return true;
            case R.id.menu_matrix_restore:
                if (mCurrentDisplayMatrix == null)
                    showToast("You need to capture display matrix first");
                else
                    mAttacher.setDisplayMatrix(mCurrentDisplayMatrix);
                return true;
            case R.id.menu_matrix_capture:
                mCurrentDisplayMatrix = mAttacher.getDisplayMatrix();
                return true;
            case R.id.extract_visible_bitmap:
                try {
                    Bitmap bmp = mAttacher.getVisibleRectangleBitmap();
                    File tmpFile = File.createTempFile("photoview", ".png",
                            Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS));
                    FileOutputStream out = new FileOutputStream(tmpFile);
                    bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
                    out.close();
                    Intent share = new Intent(Intent.ACTION_SEND);
                    share.setType("image/png");
                    share.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(tmpFile));
                    startActivity(share);
                    Toast.makeText(this, String.format("Extracted into: %s", tmpFile.getAbsolutePath()), Toast.LENGTH_SHORT).show();
                } catch (Throwable t) {
                    t.printStackTrace();
                    Toast.makeText(this, "Error occured while extracting bitmap", Toast.LENGTH_SHORT).show();
                }
                return true;
        }

        return super.onOptionsItemSelected(item);
    }

    private class PhotoTapListener implements OnPhotoTapListener {

        @Override
        public void onPhotoTap(View view, float x, float y) {
            float xPercentage = x * 100f;
            float yPercentage = y * 100f;

            showToast(String.format(PHOTO_TAP_TOAST_STRING, xPercentage, yPercentage, view == null ? 0 : view.getId()));
        }
    }

    private void showToast(CharSequence text) {
        if (null != mCurrentToast) {
            mCurrentToast.cancel();
        }

        mCurrentToast = Toast.makeText(SimpleSampleActivity.this, text, Toast.LENGTH_SHORT);
        mCurrentToast.show();
    }

    private class MatrixChangeListener implements OnMatrixChangedListener {

        @Override
        public void onMatrixChanged(RectF rect) {
            mCurrMatrixTv.setText(rect.toString());
        }
    }

}