clean up drawer code

app/src/main/java/com/geeksville/mesh/ui/AppDrawer.kt

@@ -0,0 +1,114 @@
+package com.geeksville.mesh.ui
+
+import androidx.annotation.DrawableRes
+import androidx.compose.Composable
+import androidx.ui.core.Modifier
+import androidx.ui.core.Text
+import androidx.ui.foundation.shape.corner.RoundedCornerShape
+import androidx.ui.graphics.Color
+import androidx.ui.layout.*
+import androidx.ui.material.Button
+import androidx.ui.material.Divider
+import androidx.ui.material.MaterialTheme
+import androidx.ui.material.TextButtonStyle
+import androidx.ui.material.surface.Surface
+import androidx.ui.tooling.preview.Preview
+import androidx.ui.unit.dp
+import com.geeksville.mesh.R
+
+
+@Composable
+fun AppDrawer(
+    currentScreen: ScreenInfo,
+    closeDrawer: () -> Unit
+) {
+    Column(modifier = LayoutSize.Fill) {
+        Spacer(LayoutHeight(24.dp))
+        Row(modifier = LayoutPadding(16.dp)) {
+            VectorImage(
+                id = R.drawable.ic_launcher_new_foreground,
+                tint = (MaterialTheme.colors()).primary
+            )
+            Spacer(LayoutWidth(8.dp))
+            // VectorImage(id = R.drawable.ic_launcher_new_foreground)
+        }
+        Divider(color = Color(0x14333333))
+
+        @Composable
+        fun ScreenButton(screen: ScreenInfo) {
+            DrawerButton(
+                icon = screen.icon,
+                label = screen.label,
+                isSelected = currentScreen == screen
+            ) {
+                navigateTo(screen)
+                closeDrawer()
+            }
+        }
+
+        ScreenButton(Screen.messages)
+        ScreenButton(Screen.users)
+        ScreenButton(Screen.channel)
+        ScreenButton(Screen.settings)
+    }
+}
+
+@Composable
+private fun DrawerButton(
+    modifier: Modifier = Modifier.None,
+    @DrawableRes icon: Int,
+    label: String,
+    isSelected: Boolean,
+    action: () -> Unit
+) {
+    val colors = MaterialTheme.colors()
+    val textIconColor = if (isSelected) {
+        colors.primary
+    } else {
+        colors.onSurface.copy(alpha = 0.6f)
+    }
+    val backgroundColor = if (isSelected) {
+        colors.primary.copy(alpha = 0.12f)
+    } else {
+        colors.surface
+    }
+
+    Surface(
+        modifier = modifier + LayoutPadding(
+            left = 8.dp,
+            top = 8.dp,
+            right = 8.dp,
+            bottom = 0.dp
+        ),
+        color = backgroundColor,
+        shape = RoundedCornerShape(4.dp)
+    ) {
+        Button(onClick = action, style = TextButtonStyle()) {
+            Row {
+                VectorImage(
+                    modifier = LayoutGravity.Center,
+                    id = icon,
+                    tint = textIconColor
+                )
+                Spacer(LayoutWidth(16.dp))
+                Text(
+                    text = label,
+                    style = (MaterialTheme.typography()).body2.copy(
+                        color = textIconColor
+                    ),
+                    modifier = LayoutWidth.Fill
+                )
+            }
+        }
+    }
+}
+
+
+@Preview
+@Composable
+fun previewDrawer() {
+    AppDrawer(
+        currentScreen = AppStatus.currentScreen,
+        closeDrawer = { }
+    )
+}