Expand the emoji picker to full height when the keyboard is shown (#7382)

* Expand the emoji picker to full height when the keyboard is shown

The picker content is rendered with fillMaxSize, so the sheet measures itself to
the full window height. That makes the partially expanded anchor available, and
the modal sheet auto-shows at that anchor, half way down the screen.

The sheet reserves the IME inset through its content window insets, but applies
that padding at its own bottom edge, which is off-screen while it rests half way
down. The band that is both on-screen and above the keyboard is then only about
a tenth of the screen, which is why the matching emoji end up behind it.

Expand the sheet while the keyboard is visible so its bottom edge returns to the
screen edge and the inset it already reserves lands on top of the keyboard.
Modifier.imePadding on the sheet content is not an option: the sheet applies the
insets with windowInsetsPadding, which consumes them, so a nested imePadding
reads zero.

* Cover the keyboard driven sheet expansion with a test

The IME reaction moves into ExpandSheetWhenImeIsVisible so a Robolectric test can
drive it: dispatching window insets to the composition flips
WindowInsets.isImeVisible, and the sheet state is observable from the test. Both
the shown and the hidden case are asserted, which is the patch coverage this
change was missing.

* Do not leave a blank strip below the expanded emoji search

The 10dp of bottom padding on the search bar separates the collapsed
field from the category tabs underneath it. It stayed applied once the
search bar expanded to fill the picker, so the picker stopped 10dp short
of its own bottom edge.

That strip used to sit below the visible part of a half height sheet.
Now that the sheet expands against the keyboard it reads as a gap
between the results and the keyboard, so only pad while collapsed.

libraries/emoji/impl/build.gradle.kts

@@ -36,5 +36,5 @@ dependencies {
     implementation(libs.matrix.emojibase.bindings)
 
     testImplementation(projects.libraries.matrix.test)
-    testCommonDependencies(libs)
+    testCommonDependencies(libs, includeTestComposeView = true)
 }

libraries/emoji/impl/src/main/kotlin/io/element/android/libraries/emoji/impl/picker/EmojiPickerView.kt

@@ -62,7 +62,7 @@ internal fun EmojiPickerView(
 
     Column(modifier) {
         SearchBar(
-            modifier = Modifier.padding(bottom = 10.dp),
+            modifier = Modifier.padding(bottom = if (state.isSearchActive) 0.dp else 10.dp),
             queryState = state.searchQuery,
             resultState = state.searchResults,
             active = state.isSearchActive,

libraries/emoji/impl/src/test/kotlin/io/element/android/libraries/emoji/impl/picker/EmojiPickerViewTest.kt

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+@file:OptIn(ExperimentalTestApi::class)
+
+package io.element.android.libraries.emoji.impl.picker
+
+import androidx.activity.ComponentActivity
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.size
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.test.AndroidComposeUiTest
+import androidx.compose.ui.test.ExperimentalTestApi
+import androidx.compose.ui.test.assertIsEqualTo
+import androidx.compose.ui.test.getBoundsInRoot
+import androidx.compose.ui.test.hasScrollToIndexAction
+import androidx.compose.ui.test.v2.runAndroidComposeUiTest
+import androidx.compose.ui.unit.dp
+import io.element.android.emojibasebindings.Emoji
+import io.element.android.libraries.designsystem.theme.components.SearchBarResultState
+import io.element.android.tests.testutils.robolectric.RobolectricTest
+import kotlinx.collections.immutable.persistentListOf
+import kotlinx.collections.immutable.persistentSetOf
+import org.junit.Test
+import org.robolectric.annotation.Config
+
+private val PICKER_HEIGHT = 600.dp
+
+class EmojiPickerViewTest : RobolectricTest() {
+    @Config(qualifiers = "w400dp-h800dp")
+    @Test
+    fun `the search results reach the bottom of the picker`() = runAndroidComposeUiTest<ComponentActivity> {
+        setEmojiPickerView()
+        onNode(hasScrollToIndexAction())
+            .getBoundsInRoot()
+            .bottom
+            .assertIsEqualTo(PICKER_HEIGHT, "emoji grid bottom")
+    }
+}
+
+private fun AndroidComposeUiTest<ComponentActivity>.setEmojiPickerView() {
+    setContent {
+        Box(Modifier.size(400.dp, PICKER_HEIGHT)) {
+            EmojiPickerView(
+                state = aDefaultEmojiPickerState(
+                    isSearchActive = true,
+                    searchQuery = "smile",
+                    searchResults = SearchBarResultState.Results(
+                        persistentListOf(
+                            Emoji(
+                                hexcode = "0x00",
+                                label = "grinning face",
+                                tags = persistentListOf("grinning"),
+                                shortcodes = persistentListOf("smile"),
+                                unicode = "😀",
+                                skins = null,
+                            ),
+                        )
+                    ),
+                ),
+                onSelectEmoji = {},
+                selectedEmojis = persistentSetOf(),
+                modifier = Modifier.fillMaxSize(),
+            )
+        }
+    }
+}