Release 1.0.6

germainkevinbusiness · Oct 4, 2022 · a2ae642 · a2ae642
1 parent 35a82f9
commit a2ae642
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Showing 3 changed files with 87 additions and 66 deletions.
diff --git a/app/src/main/java/com/germainkevin/collapsingtopbarcompose/MainActivity.kt b/app/src/main/java/com/germainkevin/collapsingtopbarcompose/MainActivity.kt
@@ -4,25 +4,25 @@ import android.os.Bundle
 import android.view.Window
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
+import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
-import androidx.compose.material.Scaffold
 import androidx.compose.material.ScaffoldState
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.KeyboardArrowDown
-import androidx.compose.material.icons.filled.KeyboardArrowUp
-import androidx.compose.material.icons.filled.MoreHoriz
 import androidx.compose.material.rememberScaffoldState
-import androidx.compose.material3.*
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.unit.dp
-import com.germainkevin.collapsingtopbar.*
+import com.germainkevin.collapsingtopbar.CollapsingTopBar
+import com.germainkevin.collapsingtopbar.CollapsingTopBarState
+import com.germainkevin.collapsingtopbar.rememberCollapsingTopBarScrollBehavior
 import com.germainkevin.collapsingtopbarcompose.ui.*
 import com.germainkevin.collapsingtopbarcompose.ui.theme.CollapsingTopBarComposeTheme
 
@@ -71,6 +71,7 @@ class MainActivity : ComponentActivity() {
     }
 }
 
+@OptIn(ExperimentalFoundationApi::class)
 @Composable
 private fun HomeScreen(
     scaffoldState: ScaffoldState,
@@ -82,28 +83,27 @@ private fun HomeScreen(
         isExpandedWhenFirstDisplayed = false,
         centeredTitleWhenCollapsed = false,
         centeredTitleAndSubtitle = true,
-        expandedTopBarMaxHeight = 200.dp,
+        expandedTopBarMaxHeight = 156.dp,
     )
     val isCollapsed = scrollBehavior.currentState == CollapsingTopBarState.COLLAPSED
     val isExpanded = scrollBehavior.currentState == CollapsingTopBarState.EXPANDED
-    Scaffold(
+    Column(
         modifier = Modifier.nestedScroll(scrollBehavior.nestedScrollConnection),
-        scaffoldState = scaffoldState,
-        topBar = {
-            CollapsingTopBar(
-                scrollBehavior = scrollBehavior,
-                colors = collapsingTopBarColors(window),
-                title = TitleText,
-                expandedTitle = ExpandedTitleText,
-                subtitle = { SubtitleText(contacts) },
-                navigationIcon = { NavigationIcon() },
-                actions = { MoreMenuIcons(scrollBehavior, isCollapsed, isExpanded) },
-            )
-        },
-    ) { contentPadding ->
+    ) {
+        CollapsingTopBar(
+            scrollBehavior = scrollBehavior,
+            colors = collapsingTopBarColors(window),
+            title = TitleText,
+            expandedTitle = ExpandedTitleText,
+            subtitle = { SubtitleText(contacts) },
+            navigationIcon = { NavigationIcon() },
+            actions = { MoreMenuIcons(scrollBehavior, isCollapsed, isExpanded) },
+        )
         LazyColumn(
-            modifier = Modifier.background(MaterialTheme.colorScheme.background),
-            contentPadding = contentPadding,
+            modifier = Modifier
+                .weight(1f)
+                .background(MaterialTheme.colorScheme.background),
+//            contentPadding = contentPadding,
             verticalArrangement = Arrangement.spacedBy(8.dp)
         ) {
             items(contacts) {

diff --git a/...gtopbar/src/main/java/com/germainkevin/collapsingtopbar/CollapsingTopBarScrollBehavior.kt b/...gtopbar/src/main/java/com/germainkevin/collapsingtopbar/CollapsingTopBarScrollBehavior.kt
@@ -8,7 +8,6 @@ import androidx.compose.ui.input.nestedscroll.NestedScrollSource
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
-import timber.log.Timber
 import kotlin.math.roundToInt
 
 /**
@@ -117,6 +116,8 @@ interface CollapsingTopBarScrollBehavior {
      * collapsed
      * */
     val collapsedTitleAlpha: @Composable () -> State<Float>
+
+    var ignorePreScrollDetection: Boolean
 }
 
 class DefaultBehaviorOnScroll(
@@ -158,34 +159,31 @@ class DefaultBehaviorOnScroll(
 
     override var offsetLimit: Float = (expandedTopBarMaxHeight - collapsedTopBarHeight).value
 
+    override var ignorePreScrollDetection: Boolean by mutableStateOf(false)
+
     override val nestedScrollConnection = object : NestedScrollConnection {
 
         override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
 
             if (!isAlwaysCollapsed) {
-
-                val availableY = available.y.toInt()
-                val newOffset = (topBarOffset + availableY)
-                val coerced = newOffset.coerceIn(minimumValue = -offsetLimit, maximumValue = 0f)
-                topBarOffset = coerced
-                val newHeight = expandedTopBarMaxHeight + topBarOffset.roundToInt().dp
-
-                if (topBarOffset == 0f) {
-                    trackOffSetIsZero += 1
-                }
-
-                // Just keeping trackOffSetIsZero from storing high numbers that are above 3
-                if (trackOffSetIsZero > 6) {
-                    trackOffSetIsZero = 3
-                }
-
-                if (!isExpandedWhenFirstDisplayed && trackOffSetIsZero >= 3) {
-                    currentTopBarHeight = newHeight
-                } else if (isExpandedWhenFirstDisplayed) {
-                    currentTopBarHeight = newHeight
+                if (!ignorePreScrollDetection) {
+                    val availableY = available.y.toInt()
+                    val newOffset = (topBarOffset + availableY)
+                    val coerced = newOffset.coerceIn(minimumValue = -offsetLimit, maximumValue = 0f)
+                    topBarOffset = coerced
+                    val newHeight = expandedTopBarMaxHeight + topBarOffset.roundToInt().dp
+
+                    incrementTopBarOffset()
+                    plateauTopBarOffset()
+
+                    if (!isExpandedWhenFirstDisplayed && trackOffSetIsZero >= 3) {
+                        currentTopBarHeight = newHeight
+                    } else if (isExpandedWhenFirstDisplayed) {
+                        currentTopBarHeight = newHeight
+                    }
+
+                    defineCurrentState()
                 }
-
-                defineCurrentState()
             }
 
             return Offset.Zero
@@ -200,6 +198,19 @@ class DefaultBehaviorOnScroll(
         getCollapsedTitleAlpha()
     }
 
+    private fun incrementTopBarOffset() {
+        if (topBarOffset == 0f) {
+            trackOffSetIsZero += 1
+        }
+    }
+
+    private fun plateauTopBarOffset() {
+        // Just keeping trackOffSetIsZero from storing high numbers that are above 3
+        if (trackOffSetIsZero > 6) {
+            trackOffSetIsZero = 3
+        }
+    }
+
     /**
      * In order to know the alpha value between 0F and 1F of the "expandedTitle subtitle column",
      * we will use the height of the [CollapsingTopBar] which is the [currentTopBarHeight].

diff --git a/collapsingtopbar/src/main/java/com/germainkevin/collapsingtopbar/Constants.kt b/collapsingtopbar/src/main/java/com/germainkevin/collapsingtopbar/Constants.kt
@@ -6,13 +6,13 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.State
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.unit.dp
 import kotlinx.coroutines.*
+import timber.log.Timber
 
 /**
  * The default collapsed height of the [CollapsingTopBar]
@@ -94,7 +94,7 @@ internal val collapsedTitle: @Composable (Boolean, Float, @Composable () -> Unit
         val exitAnimation = if (centeredTitleAndSubtitle)
             slideOutVertically() + fadeOut() else fadeOut()
         AnimatedVisibility(
-            visible = collapsedTitleAlpha in 0F.. 1F,
+            visible = collapsedTitleAlpha in 0F..1F,
             enter = enterAnimation,
             exit = exitAnimation
         ) { title() }
@@ -168,29 +168,33 @@ fun CollapsingTopBarScrollBehavior.collapse(
     onFinishedCollapsing: () -> Unit = {}
 ) {
     if (!isAlwaysCollapsed) {
+        ignorePreScrollDetection = true
         collapseJob?.cancel()
         collapseJob = coroutineScope.launch {
-            // Making sure the [CollapsingTopBar] can smoothly change height size
-            // Check the [CollapsingTopBarScrollBehavior.nestedScrollConnection] implementation
-            // for better understanding
-            trackOffSetIsZero = 0
-
             val ascendingDistance: IntRange =
                 collapsedTopBarHeight.value.toInt()..expandedTopBarMaxHeight.value.toInt()
             val descendingDistance = ascendingDistance.sortedDescending()
 
             for (currentHeight in descendingDistance) {
                 val valueDecreasedTo = currentTopBarHeight - steps
-                if (currentTopBarHeight - steps > collapsedTopBarHeight) {
-                    currentTopBarHeight = valueDecreasedTo
-                    defineCurrentState()
-                    delay(delay)
-                }
                 if (valueDecreasedTo <= collapsedTopBarHeight) {
+//                    topBarOffset = collapsedTopBarHeight.value
                     currentTopBarHeight = collapsedTopBarHeight
+                    Timber.d("Reached final step : collapse()")
+                    ignorePreScrollDetection = false
+                    // Making sure the [CollapsingTopBar] can smoothly change height size
+                    // Check the [CollapsingTopBarScrollBehavior.nestedScrollConnection] implementation
+                    // for better understanding
+                    trackOffSetIsZero = 0
                     defineCurrentState()
                     onFinishedCollapsing()
                 }
+                if (currentTopBarHeight - steps > collapsedTopBarHeight) {
+//                    topBarOffset = valueDecreasedTo.value
+                    currentTopBarHeight = valueDecreasedTo
+                    defineCurrentState()
+                    delay(delay)
+                }
             }
         }
     }
@@ -219,22 +223,28 @@ fun CollapsingTopBarScrollBehavior.expand(
     onFinishedExpanding: () -> Unit = {}
 ) {
     if (!isAlwaysCollapsed) {
+        ignorePreScrollDetection = true
         expandJob?.cancel()
         expandJob = coroutineScope.launch {
-            trackOffSetIsZero = 3
             val ascendingDistance: IntRange =
                 collapsedTopBarHeight.value.toInt()..expandedTopBarMaxHeight.value.toInt()
             for (currentHeight in ascendingDistance) {
-                if (currentTopBarHeight + steps < expandedTopBarMaxHeight) {
-                    currentTopBarHeight += steps
-                    defineCurrentState()
-                    delay(delay)
-                }
-                if (currentTopBarHeight + steps >= expandedTopBarMaxHeight) {
+                val valueIncreasedTo = currentTopBarHeight + steps
+                if (valueIncreasedTo >= expandedTopBarMaxHeight) {
+//                    topBarOffset = expandedTopBarMaxHeight.value
                     currentTopBarHeight = expandedTopBarMaxHeight
+                    Timber.d("Reached final step : expand()")
+                    ignorePreScrollDetection = false
+                    trackOffSetIsZero = 3
                     defineCurrentState()
                     onFinishedExpanding()
                 }
+                if (valueIncreasedTo < expandedTopBarMaxHeight) {
+//                    topBarOffset = valueIncreasedTo.value
+                    currentTopBarHeight = valueIncreasedTo
+                    defineCurrentState()
+                    delay(delay)
+                }
             }
         }
     }