Provide Flutter with the Ability to Manage Photos

Provide Flutter with the Ability to Manage Photos

A flutter api for photo, you can get image/video from ios or android. A plugin that provides photo album api, android ios is available, there is no ui, so that you can customize your own interface, you can make picture-related ui or plugins through the provided api

photo_manager

A flutter api for photo, you can get image/video from ios or android.

A plugin that provides photo album api, android ios is available, there is no ui, so that you can customize your own interface, you can make picture-related ui or plugins through the provided api

Other projects using this library

If you just need a picture selector, you can choose to use photo library , a multi image picker. All UI create by flutter.

name owner description pub github
photo Caijinglong A selector for multiple pictures / videos, The style is like the 6.0 version of wechat. pub package star
wechat_assets_picker fluttercandies An assets picker in WeChat 7.x style, support multi assets picking. pub package star
photo_widget fluttercandies Not just selectors, but to provide each widget as a separate component, which is convenient for quickly combining and customizing your own style. pub package star

install

Add to pubspec

the latest version is pub package

dependencies:
  photo_manager: $latest_version

import in dart code

import 'package:photo_manager/photo_manager.dart';

Usage

request permission

You must get the user's permission on android/ios.

var result = await PhotoManager.requestPermission();
if (result) {
    // success
} else {
    // fail
    /// if result is fail, you can call `PhotoManager.openSetting();`  to open android/ios applicaton's setting to get permission
}
List<AssetPathEntity> list = await PhotoManager.getAssetPathList();
name description
hasAll Is there an album containing "all"
type image/video/all , default all.
filterOption See FilterOption.
FilterOption
name description
needTitle The title attribute of the picture must be included in android (even if it is false), it is more performance-consuming in iOS, please consider whether you need it. The default is false.
sizeConstraint Constraints on resource size.
durationConstraint Constraints of time, pictures will ignore this constraint.
createDateTimeCond Create date filter
updateDateTimeCond Update date filter
orders The sort option, use addOrderOption.

Example see filter_option_page.dart.

Most classes of FilterOption support copyWith.

Get asset list from AssetPathEntity

paged
// page: The page number of the page, starting at 0.
// perPage: The number of pages per page.
final assetList = await path.getAssetListPaged(page, perPage);

The old version, it is not recommended for continued use, because there may be performance issues on some phones. Now the internal implementation of this method is also paged, but the paged count is assetCount of AssetPathEntity.

range
final assetList = await path.getAssetListRange(start: 0, end: 88); // use start and end to get asset.
// Example: 0~10 will return 10 assets. Special case: If there are only 5, return 5
Old version
AssetPathEntity data = list[0]; // 1st album in the list, typically the "Recent" or "All" album
List<AssetEntity> imageList = await data.assetList;

AssetEntity

AssetEntity entity = imageList[0];

File file = await entity.file; // image file

Uint8List originBytes = await entity.originBytes; // image/video original file content,

Uint8List thumbBytes = await entity.thumbData; // thumb data ,you can use Image.memory(thumbBytes); size is 64px*64px;

Uint8List thumbDataWithSize = await entity.thumbDataWithSize(width,height); //Just like thumbnails, you can specify your own size. unit is px; format is optional support jpg and png.

AssetType type = entity.type; // the type of asset enum of other,image,video

Duration duration = entity.videoDuration; //if type is not video, then return null.

Size size = entity.size

int width = entity.width;

int height = entity.height;

DateTime createDt = entity.createDateTime;

DateTime modifiedDt = entity.modifiedDateTime;

/// Gps info of asset. If latitude and longitude is 0, it means that no positioning information was obtained.
/// This information is not necessarily available, because the photo source is not necessarily the camera.
/// Even the camera, due to privacy issues, this property must not be available on androidQ and above.
double latitude = entity.latitude;
double longitude = entiry.longitude;

Latlng latlng = await entity.latlngAsync(); // In androidQ or higher, need use the method to get location info.

String mediaUrl = await entity.getMediaUrl(); /// It can be used in some video player plugin to preview, such as [flutter_ijkplayer](https://pub.dev/packages/flutter_ijkplayer)

String title = entity.title; // Since this property is fetched using KVO in iOS, the default is null, please use titleAsync to get it.

String relativePath = entity.relativePath; // It is always null in iOS.

About title: if the title is null or empty string, need use the titleAsync to get it. See below for the definition of attributes.

  /// It is title `MediaStore.MediaColumns.DISPLAY_NAME` in MediaStore on android.
  ///
  /// It is `PHAssetResource.filename` on iOS.
  ///
  /// Nullable in iOS. If you must need it, See [FilterOption.needTitle] or use [titleAsync].
  String title;

  /// It is [title] in Android.
  ///
  /// It is [PHAsset valueForKey:@"filename"] in iOS.
  Future<String> get titleAsync => _plugin.getTitleAsync(this);
location info of android Q

Because of AndroidQ's privacy policy issues, it is necessary to locate permissions in order to obtain the original image, and to obtain location information by reading the Exif metadata of the data.

Origin description

The originFile and originBytes will return the original content.

Not guaranteed to be available in flutter. Because flutter's Image does not support heic. The video is also the original format, non-exported format, compatibility does not guarantee usability.

Create with id

The id of the Asset corresponds to the id field of the MediaStore on android, and the localIdentity of PHAsset on iOS.

The user can store the id to any place if necessary, and next time use the AssetEntity.fromId(id) method to create the AssetEntity instace.

final asset = await AssetEntity.fromId(id);

observer

use addChangeCallback to regiser observe.

PhotoManager.addChangeCallback(changeNotify);
PhotoManager.startChangeNotify();
PhotoManager.removeChangeCallback(changeNotify);
PhotoManager.stopChangeNotify();

Clear file cache

You can use PhotoManager.clearFileCache() to clear all of cache.

The cache is generated at runtime when your call some methods. The following table will tell the user when the cache file will be generated.

Platform thumb file/originFile
Android(28 or lower) Yes No
Android(29) (requestLegacyExternalStorage) Yes No
Android(29) Yes Yes
Android(30) Yes No
iOS No Yes

Experimental

Important: The functions are not guaranteed to be fully usable, because it involves data modification, some APIs will cause irreversible deletion / movement of the data, so please use test equipment to make sure that there is no problem before using it.

Preload thumb
PhotoCachingManager().requestCacheAssets(
  assets: assets,
  option: thumbOption,
);

And, if you want to stop, call PhotoCachingManager().cancelCacheRequest();

Usually, when we preview an album, we use thumbnails. In flutter, becauseListView.builder,GridView.builderIt's all rendering that loads, but sometimes we might want to pre-load some pictures in advance to make them display faster.

Now, I try to create a caching image manager (just like PHCachingImageManager) to do it. In IOS, I use the system API directly, and Android will use glide and use glide's file cache to complete this step This function is completely optional.

Delete item

Hint: this will delete the asset from your device. For iOS, it's not just about removing from the album.

final List<String> result = await PhotoManager.editor.deleteWithIds([entity.id]); // The deleted id will be returned, if it fails, an empty array will be returned.

Tip: You need to call the corresponding PathEntity's refreshPathProperties method to refresh the latest assetCount.

And range way to get the latest data to ensure the accuracy of the current data. Such as example.

Insert new item
final AssetEntity imageEntity = await PhotoManager.editor.saveImage(uint8list); // nullable

final AssetEntity imageEntity = await PhotoManager.editor.saveImageWithPath(path); // nullable

File videoFile = File("video path");
final AssetEntity videoEntity = await await PhotoManager.editor.saveVideo(videoFile); // nullable
Copy asset

Availability:

  • iOS: some albums are smart albums, their content is automatically managed by the system and cannot be inserted manually.
  • android:
    • Before api 28, the method will copy some column from origin row.
    • In api 29 or higher, There are some restrictions that cannot be guaranteed, See document of relative_path.
Only for iOS

Create folder:

PhotoManager.editor.iOS.createFolder(
  name,
  parent: parent, // It is a folder or Recent album.
);

Create album:

PhotoManager.editor.iOS.createAlbum(
  name,
  parent: parent, // It is a folder or Recent album.
);

Remove asset in album, the asset can't be delete in device, just remove of album.

PhotoManager.editor.iOS.removeInAlbum();  // remove single asset.
PhotoManager.editor.iOS.removeAssetsInAlbum(); // Batch remove asset in album.

Delete the path in device. Both folders and albums can be deleted, except for smart albums.

PhotoManager.editor.iOS.deletePath();
Only for Android

Move asset to another album

PhotoManager.editor.android.moveAssetToAnother(entity: assetEntity, target: pathEntity);

Remove all non-existing rows. For normal Android users, this problem doesn't happened. A row record exists in the Android MediaStore, but the corresponding file has been deleted. This kind of abnormal deletion usually comes from file manager, helper to clear cache or adb. This is a very reconsuming operation. If the first one is not completed, the second one cannot be opened.

await PhotoManager.editor.android.removeAllNoExistsAsset();

iOS config

iOS plist config

Because the album is a privacy privilege, you need user permission to access it. You must to modify the Info.plist file in Runner project.

like next

    <key>NSPhotoLibraryUsageDescription</key>
    <string>App need your agree, can visit your album</string>

xcode like image in xcode

In ios11+, if you want to save or delete asset, you also need add NSPhotoLibraryAddUsageDescription to plist.

enabling localized system albums names

By default iOS will retrieve system album names only in English whatever the device's language currently set. To change this you need to open the ios project of your flutter app using xCode

in xcode

Select the project "Runner" and in the localizations table, click on the + icon

in xcode

Select the adequate language(s) you want to retrieve localized strings. Validate the popup screen without any modification Close xCode Rebuild your flutter project Now, the system albums should be displayed according to the device's language

Cache problem of iOS

iOS does not directly provide APIs to access the original files of the album. The corresponding object is PHAsset,

So when you want to use file or originFile, a cache file will be generated locally.

So if you are sensitive to space, please delete it after using file(just iOS), and if it is only used for preview, you can consider using thumb or thumbWithSize.

void useEntity(AssetEntity entity) async {
  File file = null;
  try{
    file = await entity.file;
    doUpload(); // do upload
  }finally{
    if(Platform.isIOS){
      file?.deleteSync();
    }
  }
}

android config

Cache problem of android

Because androidQ restricts the application’s ability to directly access the resource path, some large image caches will be generated. This is because: When the file/originFile attribute is used, the plugin will save a file in the cache folder and provide it to dart:io use.

Fortunately, in androidP, the path attribute can be used again, but for androidQ, this is not good news, but we can use requestLegacyExternalStorage to avoid using androidQ's api, and I also recommend you to do so. See Android Q to add the attribute.

about androidX

Google recommends completing all support-to-AndroidX migrations in 2019. Documentation is also provided.

This library has been migrated in version 0.2.2, but it brings a problem. Sometimes your upstream library has not been migrated yet. At this time, you need to add an option to deal with this problem.

The complete migration method can be consulted gitbook.

Android Q (android10 , API 29)

Now, the android part of the plugin uses api 29 to compile the plugin, so your android sdk environment must contain api 29 (androidQ).

AndroidQ has a new privacy policy, users can't access the original file.

If your compileSdkVersion and targetSdkVersion are both below 28, you can use PhotoManager.forceOldApi to force the old api to access the album. If you are not sure about this part, don't call this method. And, I recommand you add android:requestLegacyExternalStorage="true" to your AndroidManifest.xml, just like next.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="top.kikt.imagescannerexample">

    <application
        android:name="io.flutter.app.FlutterApplication"
        android:label="image_scanner_example"
        android:requestLegacyExternalStorage="true"
        android:icon="@mipmap/ic_launcher">
    </application>
</manifest>

Android R (android 11, API30)

Unlike androidQ, this version of requestLegacyExternalStorage is invalid, but I still recommend that you add this attribute to make it easier to use the old API on android29 of android device.

glide

Android native use glide to create image thumb bytes, version is 4.11.0.

If your other android library use the library, and version is not same, then you need edit your android project's build.gradle.

rootProject.allprojects {

    subprojects {
        project.configurations.all {
            resolutionStrategy.eachDependency { details ->
                if (details.requested.group == 'com.github.bumptech.glide'
                        && details.requested.name.contains('glide')) {
                    details.useVersion '4.11.0'
                }
            }
        }
    }
}

And, if you want to use ProGuard, you can see the ProGuard of Glide.

common issues

ios build error

if your flutter print like the log. see stackoverflow

Xcode's output:
↳
    === BUILD TARGET Runner OF PROJECT Runner WITH CONFIGURATION Debug ===
    The use of Swift 3 @objc inference in Swift 4 mode is deprecated. Please address deprecated @objc inference warnings, test your code with “Use of deprecated Swift 3 @objc inference” logging enabled, and then disable inference by changing the "Swift 3 @objc Inference" build setting to "Default" for the "Runner" target.
    === BUILD TARGET Runner OF PROJECT Runner WITH CONFIGURATION Debug ===
    While building module 'photo_manager' imported from /Users/cai/IdeaProjects/flutter/sxw_order/ios/Runner/GeneratedPluginRegistrant.m:9:
    In file included from <module-includes>:1:
    In file included from /Users/cai/IdeaProjects/flutter/sxw_order/build/ios/Debug-iphonesimulator/photo_manager/photo_manager.framework/Headers/photo_manager-umbrella.h:16:
    /Users/cai/IdeaProjects/flutter/sxw_order/build/ios/Debug-iphonesimulator/photo_manager/photo_manager.framework/Headers/MD5Utils.h:5:9: error: include of non-modular header inside framework module 'photo_manager.MD5Utils': '/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator11.2.sdk/usr/include/CommonCrypto/CommonDigest.h' [-Werror,-Wnon-modular-include-in-framework-module]
    #import <CommonCrypto/CommonDigest.h>
            ^
    1 error generated.
    /Users/cai/IdeaProjects/flutter/sxw_order/ios/Runner/GeneratedPluginRegistrant.m:9:9: fatal error: could not build module 'photo_manager'
    #import <photo_manager/ImageScannerPlugin.h>
     ~~~~~~~^
    2 errors generated.

Some articles about to use this library

How To: Create a custom media picker in Flutter to select photos and videos from the gallery

Flutter 开发日记-如何实现一个照片选择器 plugin

If you have other articles about this library, you can contact me or open PR here.

Download Details:

Author: CaiJingLong

Demo: https://kikt.top/

Source Code: https://github.com/CaiJingLong/flutter_photo_manager

flutter dart mobile-apps

Bootstrap 5 Complete Course with Examples

Bootstrap 5 Tutorial - Bootstrap 5 Crash Course for Beginners

Nest.JS Tutorial for Beginners

Hello Vue 3: A First Look at Vue 3 and the Composition API

Building a simple Applications with Vue 3

Deno Crash Course: Explore Deno and Create a full REST API with Deno

How to Build a Real-time Chat App with Deno and WebSockets

Convert HTML to Markdown Online

HTML entity encoder decoder Online

Google's Flutter 1.20 stable announced with new features - Navoki

Google has announced new flutter 1.20 stable with many improvements, and features, enabling flutter for Desktop and Web

Top 25 Flutter Mobile App Templates in 2020

Flutter has been booming worldwide from the past few years. While there are many popular mobile app development technologies out there, Flutter has managed to leave its mark in the mobile application development world. In this article, we’ve curated the best Flutter app templates available on the market as of July 2020.

Flutter App Development Trends 2020

As the new decade dawns upon us, a slew of technologies has been making a lot of noise to grab the developers’ attention. While native app development is going strong, the trade winds are now blowing towards going cross-platform.

How To Succeed In Mobile App Wireframe Design?

This article covers everything about mobile app wireframe design: what to do and what not, tools used in designing a mobile or web app wireframe, and more.

What is Flutter and why you should learn it?

Flutter is an open-source UI toolkit for mobile developers, so they can use it to build native-looking Android and iOS applications from the same code base for both platforms. Flutter is also working to make Flutter apps for Web, PWA (progressive Web-App) and Desktop platform (Windows,macOS,Linux).