Reimplement conversation action mode to not use system actionmode.

app/src/main/java/org/thoughtcrime/securesms/components/compose/ActionModeTopBar.kt

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.components.compose
+
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.res.vectorResource
+import androidx.compose.ui.tooling.preview.PreviewLightDark
+import org.signal.core.ui.compose.IconButtons
+import org.signal.core.ui.compose.Previews
+import org.thoughtcrime.securesms.R
+
+/**
+ * A consistent ActionMode top-bar for dealing with multiselect scenarios.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ActionModeTopBar(
+  title: String,
+  onCloseClick: () -> Unit,
+  toolbarColor: Color? = null,
+  windowInsets: WindowInsets = TopAppBarDefaults.windowInsets
+) {
+  TopAppBar(
+    colors = TopAppBarDefaults.topAppBarColors(
+      containerColor = toolbarColor ?: MaterialTheme.colorScheme.surface
+    ),
+    navigationIcon = {
+      IconButtons.IconButton(onClick = onCloseClick) {
+        Icon(
+          imageVector = ImageVector.vectorResource(R.drawable.symbol_x_24),
+          contentDescription = stringResource(R.string.CallScreenTopBar__go_back)
+        )
+      }
+    },
+    title = {
+      Text(text = title)
+    },
+    windowInsets = windowInsets
+  )
+}
+
+@PreviewLightDark
+@Composable
+fun ActionModeTopBarPreview() {
+  Previews.Preview {
+    ActionModeTopBar(
+      title = "1 selected",
+      onCloseClick = {}
+    )
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/components/compose/ActionModeTopBarView.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.components.compose
+
+import android.content.Context
+import android.util.AttributeSet
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.AbstractComposeView
+import org.signal.core.ui.compose.theme.SignalTheme
+import org.thoughtcrime.securesms.util.DynamicTheme
+
+/**
+ * A View wrapper for [ActionModeTopBar] so that we can use the same UI element in View and Compose land.
+ */
+class ActionModeTopBarView @JvmOverloads constructor(
+  context: Context,
+  attrs: AttributeSet? = null,
+  defStyleAttr: Int = 0
+) : AbstractComposeView(context, attrs, defStyleAttr) {
+
+  var title by mutableStateOf("")
+  var onCloseClick: () -> Unit by mutableStateOf({})
+
+  @Composable
+  override fun Content() {
+    SignalTheme(isDarkMode = DynamicTheme.isDarkTheme(context)) {
+      Surface(
+        color = Color.Transparent,
+        contentColor = MaterialTheme.colorScheme.onSurface
+      ) {
+        ActionModeTopBar(
+          title = title,
+          toolbarColor = Color.Transparent,
+          onCloseClick = onCloseClick,
+          windowInsets = WindowInsets()
+        )
+      }
+    }
+  }
+}