Feature/search tag

app/src/androidTest/java/com/github/swent/echo/compose/components/MainScreenTagsTest.kt

@@ -0,0 +1,40 @@
+package com.github.swent.echo.compose.components
+
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.performClick
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.github.swent.echo.data.model.Tag
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class MainScreenTagsTest {
+    @get:Rule val composeTestRule = createComposeRule()
+    private var tagClicked: Tag? = null
+
+    @Before
+    fun setUp() {
+        tagClicked = null
+    }
+
+    @Test
+    fun showTagText() {
+        val tagList = listOf(Tag("Tag1", "Sports"), Tag("Tag2", "Music"))
+        composeTestRule.setContent { TagUI(tags = tagList, null) {} }
+        composeTestRule.onNodeWithText("Sports").assertExists()
+        composeTestRule.onNodeWithText("Music").assertExists()
+    }
+
+    @Test
+    fun clickTag() {
+        val tagList = listOf(Tag("Tag1", "Sports"), Tag("Tag2", "Music"))
+        composeTestRule.setContent { TagUI(tags = tagList, null) { tagClicked = it } }
+        composeTestRule.onNodeWithText("Sports").performClick()
+        assert(tagClicked != null && tagClicked!!.name == "Sports")
+        composeTestRule.onNodeWithText("Music").performClick()
+        assert(tagClicked != null && tagClicked!!.name == "Music")
+    }
+}

app/src/main/java/com/github/swent/echo/ExcludeFromJacocoGeneratedReport.kt

@@ -0,0 +1,5 @@
+package com.github.swent.echo
+
+@Retention(AnnotationRetention.RUNTIME)
+@Target(AnnotationTarget.FUNCTION)
+internal annotation class ExcludeFromJacocoGeneratedReport

app/src/main/java/com/github/swent/echo/compose/components/MainscreenTagsFilter.kt

@@ -0,0 +1,99 @@
+@file:JvmName("MainScreenTagsFilterKt")
+
+package com.github.swent.echo.compose.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyRow
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.github.swent.echo.ExcludeFromJacocoGeneratedReport
+import com.github.swent.echo.data.model.Tag
+
+/*
+ * TagUI is a composable that displays a tag.
+ * tags: List of tags to display, fetch the most recent or the most common tags from the repository.
+ */
+
+@Composable
+fun TagUI(tags: List<Tag>, selectedTagId: String?, onTagClick: (Tag) -> Unit) {
+    val lazyListState = rememberLazyListState()
+    var selectTag by remember { mutableStateOf(selectedTagId) }
+
+    Column(modifier = Modifier) {
+        LazyRow(
+            modifier = Modifier.padding(8.dp),
+            state = lazyListState,
+            horizontalArrangement = Arrangement.spacedBy(8.dp)
+        ) {
+            items(tags) { tag ->
+                TagItem(
+                    tag = tag,
+                    isSelected = tag.tagId == selectTag,
+                    onClick = {
+                        selectTag = tag.tagId
+                        onTagClick(tag)
+                    }
+                )
+            }
+        }
+    }
+}
+
+/*
+ * TagItem is a composable that highlights the selected tag.
+ */
+@Composable
+fun TagItem(tag: Tag, isSelected: Boolean, onClick: () -> Unit) {
+    val colors = MaterialTheme.colorScheme
+    val backgroundColor = if (isSelected) colors.primary else colors.inverseOnSurface
+    val contentColor = if (isSelected) colors.onPrimary else colors.onSurface
+
+    FilledTonalButton(
+        onClick = onClick,
+        contentPadding = PaddingValues(0.dp),
+        colors =
+            ButtonDefaults.buttonColors(
+                containerColor = backgroundColor,
+                contentColor = contentColor,
+            )
+    ) {
+        Text(
+            text = tag.name,
+            color = contentColor,
+            fontSize = 16.sp,
+        )
+    }
+}
+// excluding this preview function
+@ExcludeFromJacocoGeneratedReport
+@Preview
+@Composable
+fun PreviewTagUI() {
+    val tags =
+        listOf(
+            Tag("SP", "Sports"),
+            Tag("MU", "Music"),
+            Tag("SO", "Social"),
+            Tag("AR", "Arts"),
+            Tag("GA", "Games"),
+            Tag("PO", "Politics"),
+            Tag("TE", "Tech")
+        )
+    MaterialTheme { TagUI(tags = tags, null) {} }
+}