add code floading

app/src/main/java/io/github/rosemoe/sora/app/MainActivity.kt

@@ -60,6 +60,7 @@ import io.github.rosemoe.sora.event.SelectionChangeEvent
 import io.github.rosemoe.sora.event.SideIconClickEvent
 import io.github.rosemoe.sora.event.TextSizeChangeEvent
 import io.github.rosemoe.sora.graphics.inlayHint.ColorInlayHintRenderer
+import io.github.rosemoe.sora.graphics.inlayHint.GhostTextInlayHintRenderer
 import io.github.rosemoe.sora.graphics.inlayHint.TextInlayHintRenderer
 import io.github.rosemoe.sora.lang.EmptyLanguage
 import io.github.rosemoe.sora.lang.JavaLanguageSpec
@@ -68,8 +69,10 @@ import io.github.rosemoe.sora.lang.analysis.AsyncIncrementalAnalyzeManager
 import io.github.rosemoe.sora.lang.diagnostic.DiagnosticRegion
 import io.github.rosemoe.sora.lang.styling.color.ConstColor
 import io.github.rosemoe.sora.lang.styling.inlayHint.ColorInlayHint
+import io.github.rosemoe.sora.lang.styling.inlayHint.GhostTextInlayHint
 import io.github.rosemoe.sora.lang.styling.inlayHint.InlayHintProvider
 import io.github.rosemoe.sora.lang.styling.inlayHint.TextInlayHint
+import io.github.rosemoe.sora.lang.styling.inlayHint.addGhostText
 import io.github.rosemoe.sora.langs.java.JavaLanguage
 import io.github.rosemoe.sora.langs.monarch.MonarchColorScheme
 import io.github.rosemoe.sora.langs.monarch.MonarchLanguage
@@ -225,10 +228,12 @@ class MainActivity : AppCompatActivity() {
         binding.editor.apply {
             registerInlayHintRenderers(
                 TextInlayHintRenderer.DefaultInstance,
-                ColorInlayHintRenderer.DefaultInstance
+                ColorInlayHintRenderer.DefaultInstance,
+                GhostTextInlayHintRenderer.DefaultInstance
             )
             typefaceText = typeface
             props.stickyScroll = true
+            props.foldingEnabled = true
             setLineSpacing(2f, 1.1f)
             nonPrintablePaintingFlags =
                 CodeEditor.FLAG_DRAW_WHITESPACE_LEADING or CodeEditor.FLAG_DRAW_LINE_SEPARATOR or CodeEditor.FLAG_DRAW_WHITESPACE_IN_SELECTION or CodeEditor.FLAG_DRAW_SOFT_WRAP
@@ -588,10 +593,20 @@ class MainActivity : AppCompatActivity() {
 
                 demoInlayHintProvider?.let { binding.editor.unregisterInlayHintProvider(it) }
                 if ("big_sample" !in name) {
+                    val lineCount = binding.editor.text.lineCount
                     demoInlayHintProvider = InlayHintProvider { container ->
                         container.add(ColorInlayHint(10, 30, ConstColor("#f44336")))
                         container.add(TextInlayHint(29, 7, "^DigitTens"))
                         container.add(TextInlayHint(100, 1, "^Numbers"))
+                        // Ghost text demo (single line)
+                        container.add(GhostTextInlayHint(11, 40, " // RED color value"))
+                        // Ghost text demo (multi-line)
+                        container.addGhostText(
+                            100, 0,
+                            "    private static final int GHOST_VALUE = 42;\n" +
+                                "    // end of ghost text demo",
+                            lineCount
+                        )
                     }
                     binding.editor.registerInlayHintProvider(demoInlayHintProvider!!)
                 } else {

editor/src/main/java/io/github/rosemoe/sora/I18nConfig.java

@@ -31,8 +31,8 @@
 /**
  * Map editor built-in string resources to your given string resource. Editor string resource has
  * limited i18n function, as it only contains English and Chinese.
- * <p>
- * Note that you should configure this before creating editor instances
+ *
+ * <p>Note that you should configure this before creating editor instances
  *
  * @author Rosemoe
  */
@@ -64,5 +64,4 @@ public static int getResourceId(int resId) {
     public static String getString(@NonNull Context context, int resId) {
         return context.getString(getResourceId(resId));
     }
-
 }

editor/src/main/java/io/github/rosemoe/sora/graphics/inlayHint/GhostTextInlayHintRenderer.kt

@@ -0,0 +1,84 @@
+/*******************************************************************************
+ *    sora-editor - the awesome code editor for Android
+ *    https://github.com/Rosemoe/sora-editor
+ *    Copyright (C) 2020-2025  Rosemoe
+ *
+ *     This library is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU Lesser General Public
+ *     License as published by the Free Software Foundation; either
+ *     version 2.1 of the License, or (at your option) any later version.
+ *
+ *     This library is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *     Lesser General Public License for more details.
+ *
+ *     You should have received a copy of the GNU Lesser General Public
+ *     License along with this library; if not, write to the Free Software
+ *     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
+ *     USA
+ *
+ *     Please contact Rosemoe by email 2073412493@qq.com if you need
+ *     additional information or have any questions
+ ******************************************************************************/
+
+package io.github.rosemoe.sora.graphics.inlayHint
+
+import android.graphics.Canvas
+import io.github.rosemoe.sora.graphics.InlayHintRenderParams
+import io.github.rosemoe.sora.graphics.Paint
+import io.github.rosemoe.sora.lang.styling.inlayHint.GhostTextInlayHint
+import io.github.rosemoe.sora.lang.styling.inlayHint.InlayHint
+import io.github.rosemoe.sora.widget.schemes.EditorColorScheme
+
+/**
+ * A ghost text inlay hint renderer.
+ *
+ * The ghost text is drawn with the same font size as the editor text but in
+ * the original text color with 50% transparency, so it looks like a faded
+ * preview of the suggested text.
+ *
+ * @see GhostTextInlayHint
+ * @author Ghost
+ */
+open class GhostTextInlayHintRenderer : InlayHintRenderer() {
+
+    companion object {
+        val DefaultInstance = GhostTextInlayHintRenderer()
+
+        /**
+         * Alpha value of 50% transparency
+         */
+        private const val GHOST_TEXT_ALPHA = 0x80
+    }
+
+    protected val localPaint = Paint().also { it.isAntiAlias = true }
+
+    override val typeName: String
+        get() = GhostTextInlayHint.TYPE_NAME
+
+    override fun onMeasure(
+        inlayHint: InlayHint,
+        paint: Paint,
+        params: InlayHintRenderParams
+    ): Float {
+        return paint.measureText((inlayHint as? GhostTextInlayHint)?.text ?: "")
+    }
+
+    override fun onRender(
+        inlayHint: InlayHint,
+        canvas: Canvas,
+        paint: Paint,
+        params: InlayHintRenderParams,
+        colorScheme: EditorColorScheme,
+        measuredWidth: Float
+    ) {
+        val ghostText = inlayHint as? GhostTextInlayHint ?: return
+        localPaint.typeface = paint.typeface
+        localPaint.textSize = paint.textSize
+        val baseColor = colorScheme.getColor(EditorColorScheme.TEXT_NORMAL)
+        localPaint.color = (baseColor and 0x00FFFFFF) or (GHOST_TEXT_ALPHA shl 24)
+        canvas.drawText(ghostText.text, 0f, params.textBaseline.toFloat(), localPaint)
+    }
+
+}

editor/src/main/java/io/github/rosemoe/sora/lang/styling/inlayHint/GhostTextInlayHint.kt

@@ -0,0 +1,105 @@
+/*******************************************************************************
+ *    sora-editor - the awesome code editor for Android
+ *    https://github.com/Rosemoe/sora-editor
+ *    Copyright (C) 2020-2025  Rosemoe
+ *
+ *     This library is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU Lesser General Public
+ *     License as published by the Free Software Foundation; either
+ *     version 2.1 of the License, or (at your option) any later version.
+ *
+ *     This library is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *     Lesser General Public License for more details.
+ *
+ *     You should have received a copy of the GNU Lesser General Public
+ *     License along with this library; if not, write to the Free Software
+ *     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
+ *     USA
+ *
+ *     Please contact Rosemoe by email 2073412493@qq.com if you need
+ *     additional information or have any questions
+ ******************************************************************************/
+
+package io.github.rosemoe.sora.lang.styling.inlayHint
+
+/**
+ * A ghost text inlay hint. The [text] is rendered inline like a suggestion
+ * preview, in the original text color with 50% transparency.
+ *
+ * Ghost text is a suggestion preview displayed in place of the text that would
+ * be inserted if the user accepts the suggestion. It does not modify the
+ * document content.
+ *
+ * For multi-line suggestions, use [split] to create one hint per line, or
+ * [addGhostText] to add a multi-line ghost text to an [InlayHintsContainer].
+ * The first line is anchored at the given (line, column) and following lines
+ * are anchored to the start of the following lines.
+ *
+ * @see io.github.rosemoe.sora.graphics.inlayHint.GhostTextInlayHintRenderer
+ * @author Ghost
+ */
+open class GhostTextInlayHint(
+    line: Int,
+    column: Int,
+    val text: String,
+    displaySide: CharacterSide = CharacterSide.LEFT
+) : InlayHint(line, column, TYPE_NAME, displaySide) {
+
+    companion object {
+        const val TYPE_NAME = "ghost-text"
+
+        /**
+         * Split a (potentially) multi-line ghost text into a list of
+         * [GhostTextInlayHint], one per line.
+         *
+         * The first line is anchored at the given [line] and [column], while
+         * every following line is anchored to the start (column 0) of the
+         * corresponding following line.
+         *
+         * A trailing newline in [text] does not produce an empty trailing hint.
+         * If [lineCount] is given, hints anchored past the end of the document
+         * are dropped instead of silently referencing a non-existent line.
+         */
+        fun split(
+            line: Int,
+            column: Int,
+            text: String,
+            lineCount: Int = Int.MAX_VALUE
+        ): List<GhostTextInlayHint> {
+            var lines = text.split('\n')
+            if (lines.size > 1 && lines.last().isEmpty()) {
+                lines = lines.dropLast(1)
+            }
+            val maxLine = (lineCount - 1).coerceAtLeast(0)
+            return lines.mapIndexedNotNull { index, lineText ->
+                val targetLine = line + index
+                if (targetLine > maxLine) {
+                    null
+                } else {
+                    GhostTextInlayHint(
+                        line = targetLine,
+                        column = if (index == 0) column else 0,
+                        text = lineText
+                    )
+                }
+            }
+        }
+    }
+
+}
+
+/**
+ * Add a (potentially) multi-line ghost text to this container.
+ *
+ * @see GhostTextInlayHint.split
+ */
+fun InlayHintsContainer.addGhostText(
+    line: Int,
+    column: Int,
+    text: String,
+    lineCount: Int = Int.MAX_VALUE
+) {
+    GhostTextInlayHint.split(line, column, text, lineCount).forEach(::add)
+}