Add text case changing functionality (Fixes #2390)

app/src/main/java/net/gsantner/markor/activity/DocumentEditAndViewFragment.java

@@ -652,6 +652,26 @@ public void onFsViewerConfig(GsFileBrowserOptions.Options dopt) {
                 }, 250);
                 return true;
             }
+            case R.id.action_toggle_case:
+                if (_hlEditor != null) {
+                    _hlEditor.toggleCase();
+                }
+                return true;
+            case R.id.action_switch_case:
+                if (_hlEditor != null) {
+                    _hlEditor.switchCase();
+                }
+                return true;
+            case R.id.action_capitalize_words:
+                if (_hlEditor != null) {
+                    _hlEditor.capitalizeWords();
+                }
+                return true;
+            case R.id.action_capitalize_sentences:
+                if (_hlEditor != null) {
+                    _hlEditor.capitalizeSentences();
+                }
+                return true;
             default: {
                 return super.onOptionsItemSelected(item);
             }

app/src/main/java/net/gsantner/markor/frontend/textview/HighlightingEditor.java

@@ -33,7 +33,9 @@
 import net.gsantner.opoc.format.GsTextUtils;
 import net.gsantner.opoc.wrapper.GsCallback;
 import net.gsantner.opoc.wrapper.GsTextWatcherAdapter;
+import net.gsantner.markor.util.TextCasingUtils;
 
+import java.util.Objects;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadPoolExecutor;
@@ -297,6 +299,60 @@ private int rowEnd(final int y) {
         return layout.getLineEnd(line);
     }
 
+    // Text-Casing
+    // ---------------------------------------------------------------------------------------------
+    public void toggleCase() {
+        String text = getSelectedText();
+        if (text.isEmpty()) {
+            text = Objects.requireNonNull(getText()).toString();
+        }
+        String newText = TextCasingUtils.toggleCase(text);
+        replaceSelection(newText);
+    }
+
+    public void switchCase() {
+        String text = getSelectedText();
+        if (text.isEmpty()) {
+            text = Objects.requireNonNull(getText()).toString();
+        }
+        String newText = TextCasingUtils.switchCase(text);
+        replaceSelection(newText);
+    }
+
+    public void capitalizeWords() {
+        String text = getSelectedText();
+        if (text.isEmpty()) {
+            text = Objects.requireNonNull(getText()).toString();
+        }
+        String newText = TextCasingUtils.capitalizeWords(text);
+        replaceSelection(newText);
+    }
+
+    public void capitalizeSentences() {
+        String text = getSelectedText();
+        if (text.isEmpty()) {
+            text = Objects.requireNonNull(getText()).toString();
+        }
+        String newText = TextCasingUtils.capitalizeSentences(text);
+        replaceSelection(newText);
+    }
+
+    private String getSelectedText() {
+        int start = Math.max(0, getSelectionStart());
+        int end = Math.max(0, getSelectionEnd());
+        return Objects.requireNonNull(getText()).toString().substring(start, end);
+    }
+
+    private void replaceSelection(String replacement) {
+        int start = Math.max(0, getSelectionStart());
+        int end = Math.max(0, getSelectionEnd());
+        if (start == end) { // If no selection is made, replace all the text in the document
+            setText(replacement);
+        } else { // Replace only the selected text
+            Objects.requireNonNull(getText()).replace(start, end, replacement);
+        }
+    }
+
     // Various overrides
     // ---------------------------------------------------------------------------------------------
     public void setSaveInstanceState(final boolean save) {

app/src/main/java/net/gsantner/markor/util/TextCasingUtils.java

@@ -0,0 +1,61 @@
+package net.gsantner.markor.util;
+
+public class TextCasingUtils {
+    public static String toggleCase(String text) { // Toggle all text to Uppercase or Lowercase
+        if (text.equals(text.toUpperCase())) {
+            return text.toLowerCase();
+        } else {
+            return text.toUpperCase();
+        }
+    }
+
+    public static String switchCase(String text) { // Switch the text case of each character
+        StringBuilder result = new StringBuilder();
+        for (char c : text.toCharArray()) {
+            if (Character.isUpperCase(c)) {
+                result.append(Character.toLowerCase(c));
+            } else if (Character.isLowerCase(c)) {
+                result.append(Character.toUpperCase(c));
+            } else {
+                result.append(c);
+            }
+        }
+        return result.toString();
+    }
+
+    public static String capitalizeWords(String text) { // Capitalize the first letter of each word
+        StringBuilder result = new StringBuilder();
+        boolean capitalizeNext = true;
+        for (char c : text.toCharArray()) {
+            if (Character.isWhitespace(c)) {
+                capitalizeNext = true;
+                result.append(c);
+            } else if (capitalizeNext) {
+                result.append(Character.toUpperCase(c));
+                capitalizeNext = false;
+            } else {
+                result.append(Character.toLowerCase(c));
+            }
+        }
+        return result.toString();
+    }
+
+    public static String capitalizeSentences(String text) { // Capitalize the first letter of each sentence
+        StringBuilder result = new StringBuilder();
+        boolean capitalizeNext = true;
+        for (char c : text.toCharArray()) {
+            if (c == '.' || c == '!' || c == '?') {
+                capitalizeNext = true;
+                result.append(c);
+            } else if (Character.isWhitespace(c)) {
+                result.append(c);
+            } else if (capitalizeNext) {
+                result.append(Character.toUpperCase(c));
+                capitalizeNext = false;
+            } else {
+                result.append(c);
+            }
+        }
+        return result.toString();
+    }
+}

app/src/main/res/drawable/ic_format_text_case_black_24dp.xml

@@ -0,0 +1,12 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24.0"
+    android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M16.51,3C16.82,3 17.1,3.2 17.21,3.5L22.71,19C22.85,19.39 22.64,19.82 22.25,19.96C21.86,20.1 21.43,19.89 21.29,19.5L19.87,15.5H12.76L11.2,19.52C11.05,19.91 10.62,20.1 10.23,19.95C9.84,19.8 9.65,19.37 9.8,18.98L15.8,3.48C15.91,3.19 16.2,3 16.51,3ZM16.47,5.91L13.34,14H19.34L16.47,5.91Z"/>
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M5.5,10.5L5.79,10.51C7.75,10.61 8.91,11.74 9,13.56L9,13.76V19.26C9,19.64 8.72,19.95 8.35,20L8.25,20.01C7.87,20.01 7.56,19.73 7.51,19.36L7.5,19.26L7.5,19.16C6.51,19.72 5.6,20.01 4.75,20.01C2.91,20.01 1.5,18.72 1.5,16.76C1.5,15.04 2.69,13.75 4.66,13.52C5.59,13.4 6.54,13.47 7.5,13.73C7.49,12.62 6.94,12.07 5.71,12.01C4.75,11.96 4.07,12.1 3.68,12.37C3.34,12.61 2.87,12.53 2.63,12.19C2.4,11.85 2.48,11.38 2.82,11.15C3.47,10.69 4.37,10.48 5.5,10.5ZM7.5,15.32L7.2,15.23C6.39,15.01 5.6,14.95 4.84,15.04C3.61,15.19 3,15.85 3,16.8C3,17.89 3.71,18.55 4.75,18.55C5.43,18.55 6.27,18.23 7.25,17.58L7.5,17.41V15.32Z"/>
+</vector>

app/src/main/res/menu/document__edit__menu.xml

@@ -103,6 +103,31 @@
                 android:title="@string/font_size"
                 app:showAsAction="never" />
 
+            <!-- Text Case menu -->
+            <item
+                android:id="@+id/action_text_case"
+                android:icon="@drawable/ic_format_text_case_black_24dp"
+                android:title="@string/text_case"
+                app:showAsAction="never">
+                <menu>
+                    <item
+                        android:id="@+id/action_toggle_case"
+                        android:title="@string/toggle_case" />
+
+                    <item
+                        android:id="@+id/action_switch_case"
+                        android:title="@string/switch_case" />
+
+                    <item
+                        android:id="@+id/action_capitalize_words"
+                        android:title="@string/capitalize_words" />
+
+                    <item
+                        android:id="@+id/action_capitalize_sentences"
+                        android:title="@string/capitalize_sentences" />
+                </menu>
+            </item>
+
             <!-- Format menu -->
             <item
                 android:id="@+id/submenu_format_selection"

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

@@ -477,4 +477,9 @@ work. If not, see <https://creativecommons.org/publicdomain/zero/1.0/>.
     <string name="wont_save_min_length">Files with fewer than %d characters not saved automatically in order to prevent data loss.</string>
     <string name="advanced_filtering_help"><![CDATA[<small><a href="https://www.github.com/gsantner/markor/discussions/1940">Advanced filtering syntax</a></small>]]></string>
     <string name="filter">Filter</string>
+    <string name="text_case">Text Case</string>
+    <string name="toggle_case">Toggle Case (Ex: Case->CASE->case)</string>
+    <string name="switch_case">Switch Case (Ex: CaSe->cAsE)</string>
+    <string name="capitalize_words">Capitalize Words (Ex: a note->A Note)</string>
+    <string name="capitalize_sentences">Capitalize Sentences (Ex: case->Case)</string>
 </resources>