ADFA-4419: Remote peer editor decoration API

app/src/main/java/com/itsaky/androidide/activities/editor/PeerPresenceOverlayManager.kt

@@ -0,0 +1,129 @@
+package com.itsaky.androidide.activities.editor
+
+import android.graphics.Color
+import android.graphics.drawable.GradientDrawable
+import android.view.Gravity
+import android.view.View
+import android.widget.TextView
+import io.github.rosemoe.sora.widget.CodeEditor
+import io.github.rosemoe.sora.widget.base.EditorPopupWindow
+import java.io.File
+
+/**
+ * Renders remote-collaborator presence as small named caret badges floating in the editor,
+ * one per (file, peerId). Markers are positioned in content coordinates and track scrolling
+ * via [EditorPopupWindow.FEATURE_SCROLL_AS_CONTENT]; the plugin repositions a marker by
+ * calling [addMarker] again with a new line/column on each cursor move.
+ *
+ * All methods must be called on the main thread (the editor view is touched directly).
+ */
+class PeerPresenceOverlayManager(
+    private val editorForFile: (File) -> CodeEditor?,
+) {
+
+    private val markers: HashMap<String, HashMap<String, PeerCursorWindow>> = HashMap()
+
+    fun addMarker(
+        file: File,
+        line: Int,
+        column: Int,
+        peerId: String,
+        peerName: String,
+        peerColor: Int,
+    ): Boolean {
+        val editor = editorForFile(file) ?: return false
+        val content = editor.text
+        if (line !in 0 until content.lineCount) return false
+        val safeColumn = column.coerceIn(0, content.getColumnCount(line))
+        val byPeer = markers.getOrPut(file.absolutePath) { HashMap() }
+        val existing = byPeer[peerId]
+        val window = if (existing != null && existing.boundEditor === editor) {
+            existing
+        } else {
+            existing?.dismiss()
+            PeerCursorWindow(editor).also { byPeer[peerId] = it }
+        }
+        window.update(peerName, peerColor, line, safeColumn)
+        return true
+    }
+
+    fun removeMarker(file: File, peerId: String): Boolean {
+        val removed = markers[file.absolutePath]?.remove(peerId) ?: return false
+        removed.dismiss()
+        return true
+    }
+
+    fun clear(file: File) {
+        markers.remove(file.absolutePath)?.values?.forEach { it.dismiss() }
+    }
+
+    fun clearAll() {
+        markers.values.forEach { byPeer -> byPeer.values.forEach { it.dismiss() } }
+        markers.clear()
+    }
+}
+
+class PeerCursorWindow(
+    val boundEditor: CodeEditor,
+) : EditorPopupWindow(
+    boundEditor,
+    FEATURE_SCROLL_AS_CONTENT or FEATURE_SHOW_OUTSIDE_VIEW_ALLOWED,
+) {
+
+    private val density = boundEditor.context.resources.displayMetrics.density
+
+    private val label = TextView(boundEditor.context).apply {
+        textSize = 11f
+        gravity = Gravity.CENTER
+        maxLines = 1
+        includeFontPadding = false
+        val padH = (8 * density).toInt()
+        val padV = (3 * density).toInt()
+        setPadding(padH, padV, padH, padV)
+    }
+
+    init {
+        popup.isClippingEnabled = false
+        setContentView(label)
+    }
+
+    fun update(peerName: String, peerColor: Int, line: Int, column: Int) {
+        // getOffset returns the on-screen x. If the caret is past the visible width, add a
+        // direction arrow so the badge (clamped to the edge below) signals where the peer is.
+        val rawX = boundEditor.getOffset(line, column).toInt()
+        label.text = when {
+            rawX > boundEditor.width -> "$peerName  →"
+            rawX < 0 -> "←  $peerName"
+            else -> peerName
+        }
+        label.setTextColor(contrastingTextColor(peerColor))
+        label.background = GradientDrawable().apply {
+            setColor(peerColor)
+            cornerRadius = 4 * density
+        }
+
+        label.measure(
+            View.MeasureSpec.makeMeasureSpec(boundEditor.width, View.MeasureSpec.AT_MOST),
+            View.MeasureSpec.makeMeasureSpec(boundEditor.height, View.MeasureSpec.AT_MOST),
+        )
+        val width = label.measuredWidth
+        val height = label.measuredHeight
+        setSize(width, height)
+
+        // Clamp into the visible width so a caret scrolled off to the right pins at the edge
+        // instead of vanishing. Only clamp when the editor has a known width.
+        val maxX = boundEditor.width - width
+        val x = if (maxX >= 0) rawX.coerceIn(0, maxX) else rawX
+        val y = (boundEditor.rowHeight * line) - boundEditor.offsetY - height
+        setLocationAbsolutely(x, y)
+        if (!isShowing) show()
+    }
+
+    private fun contrastingTextColor(background: Int): Int {
+        val r = Color.red(background) / 255.0
+        val g = Color.green(background) / 255.0
+        val b = Color.blue(background) / 255.0
+        val luminance = 0.2126 * r + 0.7152 * g + 0.0722 * b
+        return if (luminance > 0.6) Color.parseColor("#0A0A0A") else Color.WHITE
+    }
+}

app/src/main/java/com/itsaky/androidide/app/EditorProviderImpl.kt

@@ -3,6 +3,7 @@ package com.itsaky.androidide.app
 import android.os.Handler
 import android.os.Looper
 import androidx.lifecycle.lifecycleScope
+import com.itsaky.androidide.activities.editor.PeerPresenceOverlayManager
 import com.itsaky.androidide.activities.editor.EditorHandlerActivity
 import com.itsaky.androidide.models.Position
 import com.itsaky.androidide.models.Range
@@ -36,6 +37,9 @@ class EditorProviderImpl(
     private val activityRef = WeakReference(activity)
     private val mainHandler = Handler(Looper.getMainLooper())
     private val fileCallbacks = java.util.concurrent.CopyOnWriteArrayList<(File?) -> Unit>()
+    private val peerPresenceOverlay = PeerPresenceOverlayManager { file ->
+        activity()?.getEditorForFile(file)?.editor
+    }
 
     private val internalListener: (File?) -> Unit = { file ->
         fileCallbacks.forEach { cb ->
@@ -57,6 +61,7 @@ class EditorProviderImpl(
     fun dispose() {
         EditorEvents.removeFileChangeListener(internalListener)
         fileCallbacks.clear()
+        onMain { peerPresenceOverlay.clearAll(); true }
         activityRef.clear()
     }
 
@@ -257,6 +262,25 @@ class EditorProviderImpl(
         true
     }
 
+    override fun showPeerCursor(
+        file: File,
+        line: Int,
+        column: Int,
+        peerId: String,
+        peerName: String,
+        peerColor: Int,
+    ): Boolean = onMain {
+        peerPresenceOverlay.addMarker(file, line, column, peerId, peerName, peerColor)
+    }
+
+    override fun hidePeerCursor(file: File, peerId: String): Boolean = onMain {
+        peerPresenceOverlay.removeMarker(file, peerId)
+    }
+
+    override fun clearPeerCursors(file: File) {
+        onMain { peerPresenceOverlay.clear(file); true }
+    }
+
     /**
      * Resolves the editor for [file], validates [line] (bounds differ between edits that
      * mutate an existing line and those that insert a new one), and runs [block] inside a

app/src/main/java/com/itsaky/androidide/repositories/PluginRepositoryImpl.kt

@@ -145,6 +145,16 @@ class PluginRepositoryImpl(
             }
 
             manager.loadPlugins()
+
+            if (manager.getPlugin(pluginId) == null) {
+                // The new package replaced the previous one but failed to load. Remove the broken
+                // artifact so subsequent loadPlugins() calls don't keep retrying it.
+                finalFile.delete()
+                throw IllegalStateException(
+                    manager.getLoadError(pluginId)
+                        ?: "Plugin \"$pluginId\" was installed but failed to load."
+                )
+            }
         }.onFailure { exception ->
             Log.e(TAG, "Failed to install plugin from file: ${pluginFile.absolutePath}", exception)
         }

plugin-api/api/plugin-api.api

@@ -1226,6 +1226,7 @@ public final class com/itsaky/androidide/plugins/services/IdeCommandService$Defa
 public abstract interface class com/itsaky/androidide/plugins/services/IdeEditorService {
 	public abstract fun addFileChangeListener (Lcom/itsaky/androidide/plugins/services/FileChangeListener;)V
 	public abstract fun appendToLine (Ljava/io/File;ILjava/lang/String;)Z
+	public abstract fun clearPeerCursors (Ljava/io/File;)V
 	public abstract fun deleteLine (Ljava/io/File;I)Z
 	public abstract fun getCurrentCursorPosition ()Lcom/itsaky/androidide/plugins/services/CursorPosition;
 	public abstract fun getCurrentFile ()Ljava/io/File;
@@ -1241,6 +1242,7 @@ public abstract interface class com/itsaky/androidide/plugins/services/IdeEditor
 	public abstract fun getModifiedFiles ()Ljava/util/List;
 	public abstract fun getOpenFiles ()Ljava/util/List;
 	public abstract fun getWordAtCursor ()Ljava/lang/String;
+	public abstract fun hidePeerCursor (Ljava/io/File;Ljava/lang/String;)Z
 	public abstract fun insertLineBefore (Ljava/io/File;ILjava/lang/String;)Z
 	public abstract fun insertTextAtCursor (Ljava/lang/String;)Z
 	public abstract fun isFileModified (Ljava/io/File;)Z
@@ -1253,6 +1255,13 @@ public abstract interface class com/itsaky/androidide/plugins/services/IdeEditor
 	public abstract fun replaceRange (Ljava/io/File;Lcom/itsaky/androidide/plugins/services/SelectionRange;Ljava/lang/String;)Z
 	public abstract fun replaceSelection (Ljava/lang/String;)Z
 	public abstract fun saveCurrentFile ()Z
+	public abstract fun showPeerCursor (Ljava/io/File;IILjava/lang/String;Ljava/lang/String;I)Z
+}
+
+public final class com/itsaky/androidide/plugins/services/IdeEditorService$DefaultImpls {
+	public static fun clearPeerCursors (Lcom/itsaky/androidide/plugins/services/IdeEditorService;Ljava/io/File;)V
+	public static fun hidePeerCursor (Lcom/itsaky/androidide/plugins/services/IdeEditorService;Ljava/io/File;Ljava/lang/String;)Z
+	public static fun showPeerCursor (Lcom/itsaky/androidide/plugins/services/IdeEditorService;Ljava/io/File;IILjava/lang/String;Ljava/lang/String;I)Z
 }
 
 public abstract interface class com/itsaky/androidide/plugins/services/IdeEditorTabService {
@@ -1307,10 +1316,12 @@ public abstract interface class com/itsaky/androidide/plugins/services/IdeProjec
 	public abstract fun getCurrentProject ()Lcom/itsaky/androidide/plugins/extensions/IProject;
 	public abstract fun getModuleContext (Ljava/lang/String;)Lcom/itsaky/androidide/plugins/services/ModuleContext;
 	public abstract fun getProjectByPath (Ljava/io/File;)Lcom/itsaky/androidide/plugins/extensions/IProject;
+	public abstract fun openProject (Ljava/io/File;)Z
 }
 
 public final class com/itsaky/androidide/plugins/services/IdeProjectService$DefaultImpls {
 	public static fun getModuleContext (Lcom/itsaky/androidide/plugins/services/IdeProjectService;Ljava/lang/String;)Lcom/itsaky/androidide/plugins/services/ModuleContext;
+	public static fun openProject (Lcom/itsaky/androidide/plugins/services/IdeProjectService;Ljava/io/File;)Z
 }
 
 public abstract interface class com/itsaky/androidide/plugins/services/IdeSidebarService {

plugin-api/src/main/kotlin/com/itsaky/androidide/plugins/services/IdeServices.kt

@@ -32,6 +32,24 @@ interface IdeProjectService {
      */
     fun getProjectByPath(path: File): IProject?
 
+    /**
+     * Requests the IDE to open the project rooted at [projectDir], replacing the project
+     * that is currently open. Dispatches asynchronously: a `true` return means the open was
+     * requested and the editor is being launched, not that the project has finished loading.
+     * Poll [getCurrentProject] to observe completion.
+     *
+     * Requires the FILESYSTEM_READ permission.
+     *
+     * Default-implemented (no-op, returns false) so adding it is a backward-compatible
+     * interface extension: existing implementers and any prebuilt plugin-api lib keep
+     * compiling; the host overrides it.
+     *
+     * @param projectDir The root directory of the project to open
+     * @return true if the open request was dispatched, false if it was rejected or the IDE
+     *   has no foreground activity available to host the editor
+     */
+    fun openProject(projectDir: File): Boolean = false
+
     /**
      * Resolves the build context (compile/intermediate classpaths, runtime dex files,
      * selected variant, resource APK, and whether a build is needed) for the module that
@@ -143,6 +161,31 @@ interface IdeEditorService {
 
     fun replaceRange(file: File, range: SelectionRange, newText: String): Boolean
 
+    /**
+     * Draws (or moves) a remote peer's cursor — a small colored, named caret badge —
+     * inside the editor for [file] at the 0-based [line]/[column]. Cursors are keyed by
+     * [peerId]: calling again for the same (file, peerId) repositions the existing cursor.
+     * [peerColor] is an ARGB int. No-op (returns false) if the file isn't open in an editor.
+     * Visual overlay only — never mutates file content. Requires FILESYSTEM_READ.
+     *
+     * Default-implemented (no-op) so adding it is a backward-compatible interface extension:
+     * existing implementers and any prebuilt plugin-api lib keep compiling; the host overrides it.
+     */
+    fun showPeerCursor(
+        file: File,
+        line: Int,
+        column: Int,
+        peerId: String,
+        peerName: String,
+        peerColor: Int,
+    ): Boolean = false
+
+    /** Hides the cursor for [peerId] in [file], if present. Default-implemented no-op. */
+    fun hidePeerCursor(file: File, peerId: String): Boolean = false
+
+    /** Removes all remote peer cursors in [file]. Default-implemented no-op. */
+    fun clearPeerCursors(file: File) {}
+
     fun addFileChangeListener(listener: FileChangeListener)
 
     fun removeFileChangeListener(listener: FileChangeListener)

plugin-manager/src/main/kotlin/com/itsaky/androidide/plugins/manager/core/PluginManager.kt

@@ -64,6 +64,7 @@ import com.itsaky.androidide.plugins.extensions.BuildActionExtension
 import com.itsaky.androidide.plugins.manager.build.PluginBuildActionManager
 import com.itsaky.androidide.actions.SidebarSlotManager
 import com.itsaky.androidide.actions.SidebarSlotExceededException
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
@@ -153,6 +154,19 @@ class PluginManager private constructor(
             range: com.itsaky.androidide.plugins.services.SelectionRange,
             newText: String,
         ): Boolean = current()?.replaceRange(file, range, newText) ?: false
+        override fun showPeerCursor(
+            file: File,
+            line: Int,
+            column: Int,
+            peerId: String,
+            peerName: String,
+            peerColor: Int,
+        ): Boolean = current()?.showPeerCursor(file, line, column, peerId, peerName, peerColor) ?: false
+        override fun hidePeerCursor(file: File, peerId: String): Boolean =
+            current()?.hidePeerCursor(file, peerId) ?: false
+        override fun clearPeerCursors(file: File) {
+            current()?.clearPeerCursors(file)
+        }
         override fun addFileChangeCallback(callback: (File?) -> Unit) {
             pendingFileChangeCallbacks.add(callback)
             current()?.addFileChangeCallback(callback)
@@ -186,6 +200,7 @@ class PluginManager private constructor(
 
     private val loadedPlugins = ConcurrentHashMap<String, LoadedPlugin>()
     private val pluginStates = ConcurrentHashMap<String, Boolean>()
+    private val loadFailures = ConcurrentHashMap<String, String>()
     private val pluginRegistry = PluginRegistry(context)
     private val securityManager = PluginSecurityManager()
     private val serviceRegistry = ServiceRegistryImpl()
@@ -258,18 +273,20 @@ class PluginManager private constructor(
 
         logger.info("Found ${pluginFiles.size} plugin files")
 
+        loadFailures.clear()
+
         // Load plugins in parallel
         val loadJobs = pluginFiles.map { pluginFile ->
             async {
-                try {
-                    logger.debug("Loading plugin: ${pluginFile.name}")
-                    val result = loadPlugin(pluginFile)
-                    result.onFailure { error ->
-                        logger.error("Failed to load plugin from ${pluginFile.name}: ${error.message}", error)
-                    }
+                logger.debug("Loading plugin: ${pluginFile.name}")
+                val result = try {
+                    loadPlugin(pluginFile)
+                } catch (e: CancellationException) {
+                    throw e
                 } catch (e: Exception) {
-                    logger.error("Failed to load plugin from ${pluginFile.name}", e)
+                    Result.failure(e)
                 }
+                result.onFailure { error -> recordLoadFailure(pluginFile, error) }
             }
         }
 
@@ -759,6 +776,14 @@ class PluginManager private constructor(
     fun getPlugin(pluginId: String): IPlugin? {
         return loadedPlugins[pluginId]?.plugin
     }
+
+    fun getLoadError(pluginId: String): String? = loadFailures[pluginId]
+
+    private fun recordLoadFailure(pluginFile: File, error: Throwable) {
+        logger.error("Failed to load plugin from ${pluginFile.name}", error)
+        val id = loadAndValidate(pluginFile).getOrNull()?.first?.id ?: pluginFile.nameWithoutExtension
+        loadFailures[id] = error.message ?: error.toString()
+    }
 
     fun getAllPlugins(): List<PluginInfo> {
         return loadedPlugins.values.map { loadedPlugin ->
@@ -1122,7 +1147,8 @@ class PluginManager private constructor(
                         override fun isPathAllowed(path: File): Boolean = validator.isPathAllowed(path)
                         override fun getAllowedPaths(): List<String> = validator.getAllowedPaths()
                     }
-                }
+                },
+                activityProvider = activityProvider
             )
         }
 
@@ -1356,7 +1382,8 @@ class PluginManager private constructor(
                         override fun isPathAllowed(path: File): Boolean = validator.isPathAllowed(path)
                         override fun getAllowedPaths(): List<String> = validator.getAllowedPaths()
                     }
-                }
+                },
+                activityProvider = activityProvider
             )
         }