Add TextFields demo page (#615)

compose/mpp/demo/src/commonMain/kotlin/androidx/compose/mpp/demo/App.kt

@@ -7,6 +7,7 @@ import androidx.compose.foundation.lazy.items
 import androidx.compose.material.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.mpp.demo.textfield.TextFields
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.mutableStateListOf
@@ -26,6 +27,7 @@ val MainScreen = Screen.Selection(
     Screen.ScaffoldExample("ApplicationLayouts") { ApplicationLayouts(it) },
     Screen.Example("GraphicsLayerSettings") { GraphicsLayerSettings() },
     LazyLayouts,
+    TextFields,
 )
 
 sealed interface Screen {

compose/mpp/demo/src/commonMain/kotlin/androidx/compose/mpp/demo/textfield/TextFields.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.compose.mpp.demo.textfield
+
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.TextField
+import androidx.compose.mpp.demo.Screen
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+
+val TextFields = Screen.Selection(
+    "TextFields",
+    Screen.Example("AlmostFullscreen") {
+        AlmostFullscreen()
+    },
+)
+
+@Composable
+private fun AlmostFullscreen() {
+    val textState = remember {
+        mutableStateOf(
+            buildString {
+                repeat(100) {
+                    appendLine("Text line $it")
+                }
+            }
+        )
+    }
+    TextField(
+        textState.value, { textState.value = it },
+        Modifier.fillMaxSize().padding(vertical = 40.dp)
+    )
+}
+