Java tutorial
/* * Copyright (C) 2016 stfalcon.com * * 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 com.stfalcon.frescoimageviewer; import android.content.Context; import android.content.DialogInterface; import android.graphics.Color; import android.net.Uri; import android.support.annotation.ColorInt; import android.support.annotation.ColorRes; import android.support.annotation.DimenRes; import android.support.annotation.StyleRes; import android.support.v4.view.ViewPager; import android.support.v7.app.AlertDialog; import android.util.Log; import android.view.KeyEvent; import android.view.View; import com.facebook.drawee.generic.GenericDraweeHierarchyBuilder; import com.facebook.imagepipeline.request.ImageRequestBuilder; import java.util.ArrayList; import java.util.Arrays; import java.util.List; /* * Created by Alexander Krol (troy379) on 29.08.16. */ public class ImageViewer implements OnDismissListener, DialogInterface.OnKeyListener { private static final String TAG = ImageViewer.class.getSimpleName(); private Builder builder; private AlertDialog dialog; private ImageViewerView viewer; protected ImageViewer(Builder builder) { this.builder = builder; createDialog(); } /** * Displays the built viewer if passed images list isn't empty */ public void show() { if (!builder.dataSet.data.isEmpty()) { dialog.show(); } else { Log.w(TAG, "Images list cannot be empty! Viewer ignored."); } } public String getUrl() { return viewer.getUrl(); } private void createDialog() { viewer = new ImageViewerView(builder.context); viewer.setCustomImageRequestBuilder(builder.customImageRequestBuilder); viewer.setCustomDraweeHierarchyBuilder(builder.customHierarchyBuilder); viewer.allowZooming(builder.isZoomingAllowed); viewer.allowSwipeToDismiss(builder.isSwipeToDismissAllowed); viewer.setOnDismissListener(this); viewer.setBackgroundColor(builder.backgroundColor); viewer.setOverlayView(builder.overlayView); viewer.setImageMargin(builder.imageMarginPixels); viewer.setContainerPadding(builder.containerPaddingPixels); viewer.setUrls(builder.dataSet, builder.startPosition, builder.onOrientationListener, builder.thumbnails); viewer.setPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { @Override public void onPageSelected(int position) { if (builder.imageChangeListener != null) { builder.imageChangeListener.onImageChange(position); } } }); dialog = new AlertDialog.Builder(builder.context, getDialogStyle()).setView(viewer).setOnKeyListener(this) .create(); dialog.setOnDismissListener(new DialogInterface.OnDismissListener() { @Override public void onDismiss(DialogInterface dialogInterface) { if (builder.onDismissListener != null) { builder.onDismissListener.onDismiss(); } } }); } public void updateImages(List<?> images) { viewer.updateImages(images); } /** * Fires when swipe to dismiss was initiated */ @Override public void onDismiss() { dialog.dismiss(); } /** * Resets image on {@literal KeyEvent.KEYCODE_BACK} to normal scale if needed, otherwise - hide the viewer. */ @Override public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_UP && !event.isCanceled()) { if (viewer.isScaled()) { viewer.resetScale(); } else { dialog.cancel(); } } return true; } /** * Creates new {@code ImageRequestBuilder}. */ public static ImageRequestBuilder createImageRequestBuilder() { return ImageRequestBuilder.newBuilderWithSource(Uri.parse("")); } /** * Interface definition for a callback to be invoked when image was changed */ public interface OnImageChangeListener { void onImageChange(int position); } /** * Interface definition for a callback to be invoked when viewer was dismissed */ public interface OnDismissListener { void onDismiss(); } /** * Interface definition for a callback to be invoked when viewer was dismissed */ public interface OnOrientationListener { int OnOrientaion(int currentPosition); } private @StyleRes int getDialogStyle() { return builder.shouldStatusBarHide ? android.R.style.Theme_Translucent_NoTitleBar_Fullscreen : android.R.style.Theme_Translucent_NoTitleBar; } /** * Interface used to format custom objects into an image url. */ public interface Formatter<T> { /** * Formats an image url representation of the object. * * @param t The object that needs to be formatted into url. * @return An url of image. */ String format(T t); } public static class DataSet<T> { private List<T> data; private Formatter<T> formatter; public DataSet(List<T> data) { this.data = data; } String format(int position) { return format(data.get(position)); } String format(T t) { if (formatter == null) return t.toString(); else return formatter.format(t); } public List<T> getData() { return data; } public boolean addData(int position, List<?> data) { return this.data.addAll(position, (List<? extends T>) data); } public void updateData(List<?> data) { this.data.clear(); this.data.addAll((List<? extends T>) data); } public void setFormatter(Formatter<T> formatter) { this.formatter = formatter; } } /** * Builder class for {@link ImageViewer} */ public static class Builder<T> { private Context context; private DataSet<T> dataSet; private @ColorInt int backgroundColor = Color.BLACK; private int startPosition; private OnImageChangeListener imageChangeListener; private OnDismissListener onDismissListener; private OnOrientationListener onOrientationListener; private View overlayView; private int imageMarginPixels; private int[] containerPaddingPixels = new int[4]; private ImageRequestBuilder customImageRequestBuilder; private GenericDraweeHierarchyBuilder customHierarchyBuilder; private boolean shouldStatusBarHide = true; private boolean isZoomingAllowed = true; private boolean isSwipeToDismissAllowed = true; private List<String> thumbnails; /** * Constructor using a context and images urls array for this builder and the {@link ImageViewer} it creates. */ public Builder(Context context, T[] images) { this(context, new ArrayList<>(Arrays.asList(images))); } /** * Constructor using a context and images urls list for this builder and the {@link ImageViewer} it creates. */ public Builder(Context context, List<T> images) { this.context = context; this.dataSet = new DataSet<>(images); } /** * If you use an non-string collection, you can use custom {@link Formatter} to represent it as url. */ public Builder setFormatter(Formatter<T> formatter) { this.dataSet.formatter = formatter; return this; } /** * Set background color resource for viewer * * @return This Builder object to allow for chaining of calls to set methods */ @SuppressWarnings("deprecation") public Builder setBackgroundColorRes(@ColorRes int color) { return this.setBackgroundColor(context.getResources().getColor(color)); } public Builder setThumbnails(List<String> thumbnails) { this.thumbnails = thumbnails; return this; } /** * Set background color int for viewer * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setBackgroundColor(@ColorInt int color) { this.backgroundColor = color; return this; } /** * Set background color int for viewer * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setStartPosition(int position) { this.startPosition = position; return this; } /** * Set {@link ImageViewer.OnImageChangeListener} for viewer. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setImageChangeListener(OnImageChangeListener imageChangeListener) { this.imageChangeListener = imageChangeListener; return this; } /** * Set overlay view * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setOverlayView(View view) { this.overlayView = view; return this; } /** * Set space between the images in px. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setImageMarginPx(int marginPixels) { this.imageMarginPixels = marginPixels; return this; } /** * Set space between the images using dimension. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setImageMargin(Context context, @DimenRes int dimen) { this.imageMarginPixels = Math.round(context.getResources().getDimension(dimen)); return this; } /** * Set {@code start}, {@code top}, {@code end} and {@code bottom} padding for zooming and scrolling area in px. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setContainerPaddingPx(int start, int top, int end, int bottom) { this.containerPaddingPixels = new int[] { start, top, end, bottom }; return this; } /** * Set {@code start}, {@code top}, {@code end} and {@code bottom} padding for zooming and scrolling area using dimension. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setContainerPadding(Context context, @DimenRes int start, @DimenRes int top, @DimenRes int end, @DimenRes int bottom) { setContainerPaddingPx(Math.round(context.getResources().getDimension(start)), Math.round(context.getResources().getDimension(top)), Math.round(context.getResources().getDimension(end)), Math.round(context.getResources().getDimension(bottom))); return this; } /** * Set common padding for zooming and scrolling area in px. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setContainerPaddingPx(int padding) { this.containerPaddingPixels = new int[] { padding, padding, padding, padding }; return this; } /** * Set common padding for zooming and scrolling area using dimension. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setContainerPadding(Context context, @DimenRes int padding) { int paddingPx = Math.round(context.getResources().getDimension(padding)); setContainerPaddingPx(paddingPx, paddingPx, paddingPx, paddingPx); return this; } /** * Set status bar visibility. By default is true. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder hideStatusBar(boolean shouldHide) { this.shouldStatusBarHide = shouldHide; return this; } /** * Allow or disallow zooming. By default is true. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder allowZooming(boolean value) { this.isZoomingAllowed = value; return this; } /** * Allow or disallow swipe to dismiss gesture. By default is true. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder allowSwipeToDismiss(boolean value) { this.isSwipeToDismissAllowed = value; return this; } /** * Set {@link ImageViewer.OnDismissListener} for viewer. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setOnDismissListener(OnDismissListener onDismissListener) { this.onDismissListener = onDismissListener; return this; } /** * Set {@link ImageViewer.OnDismissListener} for viewer. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setOnOrientationListener(OnOrientationListener onOrientationListener) { this.onOrientationListener = onOrientationListener; return this; } /** * Set @{@code ImageRequestBuilder} for drawees. Use it for post-processing, custom resize options etc. * Use {@link ImageViewer#createImageRequestBuilder()} to create its new instance. * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setCustomImageRequestBuilder(ImageRequestBuilder customImageRequestBuilder) { this.customImageRequestBuilder = customImageRequestBuilder; return this; } /** * Set {@link GenericDraweeHierarchyBuilder} for drawees inside viewer. * Use it for drawee customizing (e.g. failure image, placeholder, progressbar etc.) * N.B.! Due to zoom logic there is limitation of scale type which always equals FIT_CENTER. Other values will be ignored * * @return This Builder object to allow for chaining of calls to set methods */ public Builder setCustomDraweeHierarchyBuilder(GenericDraweeHierarchyBuilder customHierarchyBuilder) { this.customHierarchyBuilder = customHierarchyBuilder; return this; } /** * Creates a {@link ImageViewer} with the arguments supplied to this builder. It does not * {@link ImageViewer#show()} the dialog. This allows the user to do any extra processing * before displaying the dialog. Use {@link #show()} if you don't have any other processing * to do and want this to be created and displayed. */ public ImageViewer build() { return new ImageViewer(this); } /** * Creates a {@link ImageViewer} with the arguments supplied to this builder and * {@link ImageViewer#show()}'s the dialog. */ public ImageViewer show() { ImageViewer dialog = build(); dialog.show(); return dialog; } } }