From 75088d8414c43e00b379eee313c47fae226520a0 Mon Sep 17 00:00:00 2001
From: Dimitry Ivanov <mail@dimitryivanov.ru>
Date: Sat, 25 Aug 2018 13:29:55 +0300
Subject: [PATCH] image-loader add support for inline data uri image references

---
 .../markwon/il/AsyncDrawableLoader.java       | 39 +++++++++++++++++-
 .../ru/noties/markwon/il/DataUriDecoder.java  | 41 +++++++++++++++++++
 2 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 markwon-image-loader/src/main/java/ru/noties/markwon/il/DataUriDecoder.java

diff --git a/markwon-image-loader/src/main/java/ru/noties/markwon/il/AsyncDrawableLoader.java b/markwon-image-loader/src/main/java/ru/noties/markwon/il/AsyncDrawableLoader.java
index 7eade398..75b61087 100644
--- a/markwon-image-loader/src/main/java/ru/noties/markwon/il/AsyncDrawableLoader.java
+++ b/markwon-image-loader/src/main/java/ru/noties/markwon/il/AsyncDrawableLoader.java
@@ -7,8 +7,10 @@ import android.os.Handler;
 import android.os.Looper;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.text.TextUtils;
 
 import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
@@ -46,6 +48,12 @@ public class AsyncDrawableLoader implements AsyncDrawable.Loader {
 
     private static final String FILE_ANDROID_ASSETS = "android_asset";
 
+    private static final String SCHEME_FILE = "file";
+    private static final String SCHEME_DATA = "data";
+
+    private static final DataUriParser DATA_URI_PARSER = DataUriParser.create();
+    private static final DataUriDecoder DATA_URI_DECODER = DataUriDecoder.create();
+
     private final OkHttpClient client;
     private final Resources resources;
     private final ExecutorService executorService;
@@ -103,9 +111,14 @@ public class AsyncDrawableLoader implements AsyncDrawable.Loader {
                 final boolean isFromFile;
 
                 final Uri uri = Uri.parse(destination);
-                if ("file".equals(uri.getScheme())) {
+                final String scheme = uri.getScheme();
+
+                if (SCHEME_FILE.equals(scheme)) {
                     item = fromFile(uri);
                     isFromFile = true;
+                } else if (SCHEME_DATA.equals(scheme)) {
+                    item = fromData(uri.getSchemeSpecificPart());
+                    isFromFile = false;
                 } else {
                     item = fromNetwork(destination);
                     isFromFile = false;
@@ -208,6 +221,30 @@ public class AsyncDrawableLoader implements AsyncDrawable.Loader {
         return out;
     }
 
+    @Nullable
+    private Item fromData(@Nullable String part) {
+
+        if (TextUtils.isEmpty(part)) {
+            return null;
+        }
+
+        final DataUri dataUri = DATA_URI_PARSER.parse(part);
+        if (dataUri == null) {
+            return null;
+        }
+
+        final byte[] bytes = DATA_URI_DECODER.decode(dataUri);
+        if (bytes == null) {
+            return null;
+        }
+
+        return new Item(
+                null,
+                dataUri.contentType(),
+                new ByteArrayInputStream(bytes)
+        );
+    }
+
     @Nullable
     private Item fromNetwork(@NonNull String destination) {
 
diff --git a/markwon-image-loader/src/main/java/ru/noties/markwon/il/DataUriDecoder.java b/markwon-image-loader/src/main/java/ru/noties/markwon/il/DataUriDecoder.java
new file mode 100644
index 00000000..ffb0d840
--- /dev/null
+++ b/markwon-image-loader/src/main/java/ru/noties/markwon/il/DataUriDecoder.java
@@ -0,0 +1,41 @@
+package ru.noties.markwon.il;
+
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.text.TextUtils;
+import android.util.Base64;
+
+public abstract class DataUriDecoder {
+
+    @Nullable
+    public abstract byte[] decode(@NonNull DataUri dataUri);
+
+    @NonNull
+    public static DataUriDecoder create() {
+        return new Impl();
+    }
+
+    static class Impl extends DataUriDecoder {
+
+        @Nullable
+        @Override
+        public byte[] decode(@NonNull DataUri dataUri) {
+
+            final String data = dataUri.data();
+
+            if (!TextUtils.isEmpty(data)) {
+                try {
+                    if (dataUri.base64()) {
+                        return Base64.decode(data.getBytes("UTF-8"), Base64.DEFAULT);
+                    } else {
+                        return data.getBytes("UTF-8");
+                    }
+                } catch (Throwable t) {
+                    return null;
+                }
+            } else {
+                return null;
+            }
+        }
+    }
+}