add LinearProgressIndicator docs

docs/03-components/10-progress-indicators/loading.mdx

@@ -0,0 +1,47 @@
+---
+title: Android
+---
+
+## Overview
+
+Orbit Compose offers multiple components to visualize loading::
+
+- [`LinearProgressIndicator`](https://kiwicom.github.io/orbit-compose/ui/kiwi.orbit.compose.ui.controls/-linear-progress-indicator.html)
+- [`LinearIndeterminateProgressIndicator`](https://kiwicom.github.io/orbit-compose/ui/kiwi.orbit.compose.ui.controls/-linear-indeterminate-progress-indicator.html)
+
+## Usage
+
+Use `LinearProgressIndicator` composable and define a state a progress value. By default, all progress value changes are animated. Pass a custom animation specification via `progressAnimationSpec`. To disable animation, use `snap()` animation.
+
+```kotlin
+@Composable
+fun Example(progress: Float) {
+    LinearProgressIndicator(
+        progress = progress,
+    )
+}
+```
+
+## UI Testing
+
+Use semantic properties and action to set progress and read the state.
+
+```kotlin
+composeTestRule.setContent {
+    LinearProgressIndicator(
+        progress = 0.4f,
+        modifier = Modifier.testTag("loader"),
+    )
+}
+
+val progressBarInfo = composeTestRule
+    .onNodeWithTag("loader")
+    .fetchSemanticsNode()
+    .config[SemanticsProperties.ProgressBarRangeInfo]
+
+Assert.assertEquals(0.4f, progressBarInfo.current)
+```
+
+## Customization
+
+To change track colors use `color` and `backgroundColor` arguments.

docs/readme.md

@@ -13,6 +13,7 @@
 1. [ButtonPrimitive](03-components/15-primitives/buttonprimitive.mdx)
 1. [Button](03-components/01-action/button.mdx)
 1. [Card](03-components/02-structure/card.mdx)
+1. [Loading / LinearProgressIndicator](03-components/10-progress-indicators/loading.mdx)
 1. [Slider](03-components/07-interaction/slider.mdx)
 1. [Tabs](03-components/02-structure/tabs.mdx)
 1. [Tile](03-components/02-structure/tile.mdx)

ui/src/test/kotlin/kiwi/orbit/compose/ui/controls/LinearProgressIndicatorTest.kt

@@ -0,0 +1,33 @@
+package kiwi.orbit.compose.ui.controls
+
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.semantics.SemanticsProperties
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithTag
+import org.junit.Assert
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+internal class LinearProgressIndicatorTest {
+    @get:Rule
+    val composeTestRule = createComposeRule()
+
+    @Test
+    fun testBasics() {
+        composeTestRule.setContent {
+            LinearProgressIndicator(
+                progress = 0.4f,
+                modifier = Modifier.testTag("loader"),
+            )
+        }
+        val progressBarInfo = composeTestRule
+            .onNodeWithTag("loader")
+            .fetchSemanticsNode()
+            .config[SemanticsProperties.ProgressBarRangeInfo]
+        Assert.assertEquals(0.4f, progressBarInfo.current)
+    }
+}