Add support for maths.

app/src/main/java/app/fedilab/android/helper/Helper.java

@@ -327,7 +327,8 @@ public class Helper {
     public static final Pattern groupPattern = Pattern.compile("(![\\w_]+)");
     public static final Pattern mentionPattern = Pattern.compile("(@[\\w_.-]?[\\w]+)");
     public static final Pattern mentionLongPattern = Pattern.compile("(@[\\w_.-]+@[a-zA-Z0-9][a-zA-Z0-9.-]{1,61}[a-zA-Z0-9](?:\\.[a-zA-Z]{2,})+)");
-    public static final Pattern mathsPattern = Pattern.compile("\\\\\\(|\\\\\\{|\\\\\\[");
+    public static final Pattern mathsPattern = Pattern.compile("\\\\\\(|\\\\\\[");
+    public static final Pattern mathsComposePattern = Pattern.compile("\\\\\\(.*\\\\\\)|\\\\\\[.*\\\\\\]");
     public static final Pattern twitterPattern = Pattern.compile("((@[\\w]+)@twitter\\.com)");
     public static final Pattern youtubePattern = Pattern.compile("(www\\.|m\\.)?(youtube\\.com|youtu\\.be|youtube-nocookie\\.com)/(((?!([\"'<])).)*)");
     public static final Pattern nitterPattern = Pattern.compile("(mobile\\.|www\\.)?twitter.com([\\w-/]+)");

app/src/main/java/app/fedilab/android/ui/drawer/ComposeAdapter.java

@@ -28,6 +28,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
+import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.Color;
@@ -531,7 +532,9 @@ public class ComposeAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder
                 if (promptDraftListener != null) {
                     promptDraftListener.promptDraft();
                 }
+                if (holder.binding.content.getSelectionStart() > 0) {
                     statusList.get(holder.getLayoutPosition()).cursorPosition = holder.binding.content.getSelectionStart();
+                }
                 //Copy/past
                 int max_car = MastodonHelper.getInstanceMaxChars(context);
                 if (currentLength > max_car) {
@@ -694,6 +697,24 @@ public class ComposeAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder
                     updateCharacterCount(holder);
                     return;
                 }
+                Matcher mathsPatterns = Helper.mathsComposePattern.matcher((s.toString()));
+                if (mathsPatterns.find()) {
+                    if (holder.binding.laTexViewContainer.getVisibility() != View.VISIBLE) {
+                        holder.binding.laTexViewContainer.setVisibility(View.VISIBLE);
+
+                        switch (context.getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK) {
+                            case Configuration.UI_MODE_NIGHT_YES:
+                                holder.binding.laTexView.setTextColor("white");
+                                break;
+                            case Configuration.UI_MODE_NIGHT_NO:
+                                holder.binding.laTexView.setTextColor("black");
+                                break;
+                        }
+                    }
+                    holder.binding.laTexView.setInputText(s.toString());
+                } else {
+                    holder.binding.laTexViewContainer.setVisibility(View.GONE);
+                }
 
                 String patternh = "^(.|\\s)*(:fedilab_hugs:)";
                 final Pattern hPattern = Pattern.compile(patternh);
@@ -1272,7 +1293,34 @@ public class ComposeAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder
 
             ComposeViewHolder holder = (ComposeViewHolder) viewHolder;
             boolean extraFeatures = sharedpreferences.getBoolean(context.getString(R.string.SET_EXTAND_EXTRA_FEATURES) + MainActivity.currentUserID + MainActivity.currentInstance, false);
+            boolean mathsComposer = sharedpreferences.getBoolean(context.getString(R.string.SET_MATHS_COMPOSER), true);
 
+            if (mathsComposer) {
+                holder.binding.buttonMathsComposer.setVisibility(View.VISIBLE);
+                holder.binding.buttonMathsComposer.setOnClickListener(v -> {
+                    int cursorPosition = holder.binding.content.getSelectionStart();
+                    AlertDialog.Builder builder = new AlertDialog.Builder(context, Helper.dialogStyle());
+                    Resources res = context.getResources();
+                    String[] formatArr = res.getStringArray(R.array.SET_MATHS_FORMAT);
+                    builder.setItems(formatArr, (dialogInterface, i) -> {
+                        if (statusDraft.text == null) {
+                            statusDraft.text = "";
+                        }
+                        if (i == 0) {
+                            statusDraft.text = new StringBuilder(statusDraft.text).insert(cursorPosition, "\\(  \\)").toString();
+                        } else {
+                            statusDraft.text = new StringBuilder(statusDraft.text).insert(cursorPosition, "\\[  \\]").toString();
+                        }
+                        statusDraft.cursorPosition = cursorPosition + 3;
+                        notifyItemChanged(position);
+                        dialogInterface.dismiss();
+                    });
+                    builder.setNegativeButton(R.string.cancel, (dialog, which) -> dialog.dismiss());
+                    builder.create().show();
+                });
+            } else {
+                holder.binding.buttonMathsComposer.setVisibility(View.GONE);
+            }
 
             holder.binding.buttonEmojiOne.setVisibility(View.VISIBLE);
             if (extraFeatures) {

app/src/main/java/app/fedilab/android/ui/drawer/StatusAdapter.java

@@ -674,9 +674,10 @@ public class StatusAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>
                         mathJaxConfig.setTextColor("white");
                         break;
                     case Configuration.UI_MODE_NIGHT_NO:
-                        mathJaxConfig.setTextColor("dark");
+                        mathJaxConfig.setTextColor("black");
                         break;
                 }
+                mathJaxConfig.setAutomaticLinebreaks(true);
                 status.mathsShown = true;
                 MathJaxView mathview = new MathJaxView(context, mathJaxConfig);
                 holder.binding.statusContentMaths.addView(mathview);

app/src/main/res/layout/drawer_status_compose.xml

@@ -32,6 +32,27 @@
         android:clipToPadding="false"
         android:orientation="vertical">
 
+        <androidx.core.widget.NestedScrollView
+            android:id="@+id/laTexView_container"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:visibility="gone"
+            app:layout_constraintBottom_toTopOf="@+id/button_emoji"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent">
+
+            <de.timfreiheit.mathjax.android.MathJaxView
+                android:id="@+id/laTexView"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_gravity="center"
+                app:automaticLinebreaks="true"
+                app:input="TeX"
+                app:output="SVG" />
+        </androidx.core.widget.NestedScrollView>
+
+
         <com.google.android.material.textfield.MaterialAutoCompleteTextView
             android:id="@+id/content_spoiler"
             android:layout_width="0dp"
@@ -44,7 +65,7 @@
             android:visibility="gone"
             app:layout_constraintEnd_toStartOf="@id/button_emoji"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toTopOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/laTexView_container"
             tools:visibility="visible" />
 
         <com.google.android.material.button.MaterialButton
@@ -55,7 +76,7 @@
             android:contentDescription="@string/add_status"
             app:icon="@drawable/ic_compose_thread_add_status"
             app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintTop_toTopOf="parent" />
+            app:layout_constraintTop_toBottomOf="@+id/laTexView_container" />
 
         <app.fedilab.android.helper.FedilabAutoCompleteTextView
             android:id="@+id/content"
@@ -103,6 +124,17 @@
             app:layout_constraintTop_toBottomOf="@id/button_emoji_one"
             tools:visibility="visible" />
 
+        <com.google.android.material.button.MaterialButton
+            android:id="@+id/button_maths_composer"
+            style="@style/Fedilab.SmallIconButton"
+            android:layout_marginEnd="6dp"
+            android:contentDescription="@string/maths_format"
+            android:visibility="gone"
+            app:icon="@drawable/ic_baseline_functions_24"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/button_text_format"
+            tools:visibility="visible" />
+
         <com.google.android.material.button.MaterialButton
             android:id="@+id/button_local_only"
             style="@style/Fedilab.SmallIconButton"
@@ -111,7 +143,7 @@
             android:visibility="gone"
             app:icon="@drawable/ic_baseline_remove_red_eye_24"
             app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/button_text_format"
+            app:layout_constraintTop_toBottomOf="@id/button_maths_composer"
             tools:visibility="visible" />
 
         <com.google.android.material.checkbox.MaterialCheckBox

app/src/main/res/values/strings.xml

@@ -763,6 +763,12 @@
         <item>Mastalab</item>
     </string-array>
 
+
+    <string-array name="SET_MATHS_FORMAT">
+        <item>Inline\nNotation that sits inline with other text\n</item>
+        <item>Display-mode\nNotation that sits on its own line\n</item>
+    </string-array>
+
     <string-array name="SET_POST_FORMAT" translatable="false">
         <item>text/plain</item>
         <item>text/html</item>
@@ -1483,6 +1489,7 @@
     <string name="SET_UNLISTED_REPLIES" translatable="false">SET_UNLISTED_REPLIES</string>
     <string name="SET_SELECTED_LANGUAGE" translatable="false">SET_SELECTED_LANGUAGE</string>
     <string name="SET_WATERMARK_TEXT" translatable="false">SET_WATERMARK_TEXT</string>
+    <string name="SET_MATHS_COMPOSER" translatable="false">SET_MATHS_COMPOSER</string>
     <string name="SET_PROXY_PASSWORD" translatable="false">SET_PROXY_PASSWORD</string>
     <string name="SET_PROXY_LOGIN" translatable="false">SET_PROXY_LOGIN</string>
     <string name="SET_ACCOUNTS_PER_CALL" translatable="false">SET_ACCOUNTS_PER_CALL</string>
@@ -2214,4 +2221,6 @@
     <string name="set_disable_release_notes">Disable release notes</string>
     <string name="set_disable_release_notes_indication">When a new version is published, you will not be alerted inside the app.</string>
     <string name="formula">Formula</string>
+    <string name="set_maths_support">Write formula</string>
+    <string name="maths_format">Maths format</string>
 </resources>

app/src/main/res/xml/pref_compose.xml

@@ -60,6 +60,12 @@
         app:key="@string/SET_WATERMARK_TEXT"
         app:useSimpleSummaryProvider="true" />
 
+    <SwitchPreferenceCompat
+        app:defaultValue="true"
+        app:iconSpaceReserved="false"
+        app:key="@string/SET_MATHS_COMPOSER"
+        app:singleLineTitle="false"
+        app:title="@string/set_maths_support" />
 
     <SwitchPreferenceCompat
         app:defaultValue="false"

mathjaxandroid/src/main/java/de/timfreiheit/mathjax/android/MathJaxConfig.java

@@ -28,6 +28,7 @@ public class MathJaxConfig {
         }
     }
 
+
     public MathJaxConfig(TypedArray attrs) {
         this();
         int inputIndex = attrs.getInteger(R.styleable.MathJaxView_input, -1);

mathjaxandroid/src/main/java/de/timfreiheit/mathjax/android/MathJaxView.java

@@ -9,17 +9,13 @@ import android.os.Handler;
 import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.view.Gravity;
-import android.view.MotionEvent;
 import android.view.View;
-import android.view.ViewConfiguration;
 import android.view.ViewGroup;
 import android.webkit.WebSettings;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 import android.widget.FrameLayout;
 
-import java.util.concurrent.atomic.AtomicReference;
-
 
 /**
  * Containerview for an WebView which renders LaTex using MathJax
@@ -88,20 +84,26 @@ public class MathJaxView extends FrameLayout {
         this.onMathJaxRenderListener = onMathJaxRenderListener;
     }
 
+    public void setTextColor(String color) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+            mWebView.evaluateJavascript("document.body.style.color=\"" + color + "\";", null);
+        }
+    }
+
     @SuppressLint({"SetJavaScriptEnabled", "AddJavascriptInterface"})
     private void init(Context context, AttributeSet attrSet, MathJaxConfig config) {
         mWebView = new WebView(context);
 
         int gravity = Gravity.START;
         boolean verticalScrollbarsEnabled = false;
-        boolean horizontalScrollbarsEnabled = true;
+        boolean horizontalScrollbarsEnabled = false;
         String textColor = config != null ? config.getTextColor() : null;
 
         if (attrSet != null) {
             TypedArray attrs = context.obtainStyledAttributes(attrSet, R.styleable.MathJaxView);
             gravity = attrs.getInteger(R.styleable.MathJaxView_android_gravity, Gravity.START);
             verticalScrollbarsEnabled = attrs.getBoolean(R.styleable.MathJaxView_verticalScrollbarsEnabled, false);
-            horizontalScrollbarsEnabled = attrs.getBoolean(R.styleable.MathJaxView_horizontalScrollbarsEnabled, true);
+            horizontalScrollbarsEnabled = attrs.getBoolean(R.styleable.MathJaxView_horizontalScrollbarsEnabled, false);
             textColor = attrs.getString(R.styleable.MathJaxView_textColor);
             config = new MathJaxConfig(attrs);
             attrs.recycle();
@@ -153,31 +155,6 @@ public class MathJaxView extends FrameLayout {
         mWebView.setHorizontalScrollBarEnabled(horizontalScrollbarsEnabled);
         mWebView.setBackgroundColor(0);
         mWebView.getSettings().setLoadWithOverviewMode(true);
-        float touchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
-        final boolean[] scrollFlag = {true};
-        AtomicReference<Float> downX = new AtomicReference<>((float) 0);
-        AtomicReference<Float> downY = new AtomicReference<>((float) 0);
-        mWebView.setOnTouchListener((View v, MotionEvent event) -> {
-            if (!scrollFlag[0] && event.getY() < getHeight() / 2) {
-
-                switch (event.getAction()) {
-                    case MotionEvent.ACTION_DOWN:
-                        downX.set(event.getX());
-                        downY.set(event.getY());
-                        break;
-                    case MotionEvent.ACTION_MOVE:
-                        if (Math.abs(event.getY() - downY.get()) < touchSlop && Math.abs(event.getX() - downX.get()) > touchSlop) {
-                            getParent().requestDisallowInterceptTouchEvent(true);
-                            scrollFlag[0] = true;
-                        }
-                        break;
-                }
-            }
-            if (event.getAction() == MotionEvent.ACTION_UP)
-                scrollFlag[0] = false;
-
-            return false;
-        });
     }
 
     /**