feat: draggable sidebar

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- Draggable sidebar
 
 ## [1.6.0] - 2026-01-30
 ### Added

app/src/main/kotlin/org/fossify/contacts/fragments/MyViewPagerFragment.kt

@@ -3,6 +3,8 @@ package org.fossify.contacts.fragments
 import android.content.Context
 import android.content.Intent
 import android.util.AttributeSet
+import android.view.MotionEvent
+import android.view.View
 import android.view.ViewGroup
 import android.widget.RelativeLayout
 import androidx.coordinatorlayout.widget.CoordinatorLayout
@@ -49,6 +51,10 @@ abstract class MyViewPagerFragment<Binding : MyViewPagerFragment.InnerBinding>(c
     var skipHashComparing = false
     var forceListRedraw = false
 
+    private var initialY = 0f
+    private var dY = 0f
+    private var isPositionRestored = false
+
     fun setupFragment(activity: SimpleActivity) {
         config = activity.config
         if (this.activity == null) {
@@ -63,6 +69,8 @@ abstract class MyViewPagerFragment<Binding : MyViewPagerFragment.InnerBinding>(c
             }
 
             innerBinding.fragmentPlaceholder2.underlineText()
+            setupDragHandle()
+            restoreSidebarPosition()
 
             when (this) {
                 is ContactsFragment -> {
@@ -379,6 +387,96 @@ abstract class MyViewPagerFragment<Binding : MyViewPagerFragment.InnerBinding>(c
         innerBinding.fragmentList.beVisibleIf(hasItemsToShow)
     }
 
+    private fun setupDragHandle() {
+        val container = innerBinding.letterFastscrollerContainer ?: return
+        val dragHandle = innerBinding.letterFastscrollerDragHandle ?: return
+        val parent = container.parent as? View ?: return
+
+        dragHandle.setOnTouchListener { v, event ->
+            when (event.action) {
+                MotionEvent.ACTION_DOWN -> {
+                    isPositionRestored = true
+                    initialY = container.y
+                    dY = event.rawY - initialY
+                    v.performClick()
+                }
+
+                MotionEvent.ACTION_MOVE -> {
+                    isPositionRestored = true
+                    var newY = event.rawY - dY
+                    val fab = innerBinding.fragmentFab
+                    val parentHeight = parent.height.toFloat()
+                    val fabY = if (fab.isVisible()) fab.y else parentHeight
+                    val maxY = (fabY - container.height).coerceAtLeast(0f)
+                    newY = newY.coerceIn(0f, maxY)
+                    container.y = newY
+                }
+
+                MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> {
+                    if (isPositionRestored && container.y != initialY) {
+                        config.sidebarYOffset = container.y + container.height
+                    }
+                }
+            }
+            true
+        }
+
+        /*
+         * To ensure the sidebar expands upwards when new characters are added (instead of pushing
+         * the dot down), we listen for layout changes and adjust the Y position if the height changes.
+         */
+        container.addOnLayoutChangeListener { _, _, top, _, bottom, _, oldTop, _, oldBottom ->
+            handleOnLayoutChange(container, parent, top, bottom, oldTop, oldBottom)
+        }
+    }
+
+    private fun handleOnLayoutChange(
+        container: ViewGroup,
+        parent: View,
+        top: Int,
+        bottom: Int,
+        oldTop: Int,
+        oldBottom: Int
+    ) {
+        if (!isPositionRestored) return
+        val oldHeight = oldBottom - oldTop
+        val newHeight = bottom - top
+        if (oldHeight > 0 && newHeight != oldHeight) {
+            val heightDiff = newHeight - oldHeight
+            val fab = innerBinding.fragmentFab
+            val parentHeight = parent.height.toFloat()
+            val fabY = if (fab.isVisible()) fab.y else parentHeight
+            val maxY = (fabY - newHeight).coerceAtLeast(0f)
+
+            val newY = (container.y - heightDiff).coerceIn(0f, maxY)
+            if (container.y != newY) {
+                container.y = newY
+            }
+            config.sidebarYOffset = container.y + newHeight
+        }
+    }
+
+    private fun restoreSidebarPosition() {
+        val container = innerBinding.letterFastscrollerContainer ?: return
+        val parent = container.parent as? View ?: return
+        container.onGlobalLayout {
+            val fab = innerBinding.fragmentFab
+            val parentHeight = parent.height.toFloat()
+            val fabY = if (fab.isVisible()) fab.y else parentHeight
+            val maxY = (fabY - container.height).coerceAtLeast(0f)
+
+            val savedBottomY = config.sidebarYOffset
+            val targetY = if (savedBottomY == 0f) {
+                0f
+            } else {
+                (savedBottomY - container.height).coerceIn(0f, maxY)
+            }
+
+            container.y = targetY
+            isPositionRestored = true
+        }
+    }
+
     abstract fun fabClicked()
 
     abstract fun placeholderClicked()
@@ -391,6 +489,8 @@ abstract class MyViewPagerFragment<Binding : MyViewPagerFragment.InnerBinding>(c
         val fragmentWrapper: RelativeLayout
         val letterFastscroller: FastScrollerView?
         val letterFastscrollerThumb: FastScrollerThumbView?
+        val letterFastscrollerContainer: ViewGroup?
+        val letterFastscrollerDragHandle: View?
         val fragmentFastscroller: RecyclerViewFastScroller?
     }
 
@@ -402,6 +502,8 @@ abstract class MyViewPagerFragment<Binding : MyViewPagerFragment.InnerBinding>(c
         override val fragmentWrapper: RelativeLayout = binding.fragmentWrapper
         override val letterFastscroller: FastScrollerView = binding.letterFastscroller
         override val letterFastscrollerThumb: FastScrollerThumbView = binding.letterFastscrollerThumb
+        override val letterFastscrollerContainer: ViewGroup = binding.letterFastscrollerContainer
+        override val letterFastscrollerDragHandle: View = binding.letterFastscrollerDragHandle
         override val fragmentFastscroller: RecyclerViewFastScroller? = null
     }
 
@@ -413,6 +515,8 @@ abstract class MyViewPagerFragment<Binding : MyViewPagerFragment.InnerBinding>(c
         override val fragmentWrapper: RelativeLayout = binding.fragmentWrapper
         override val letterFastscroller: FastScrollerView? = null
         override val letterFastscrollerThumb: FastScrollerThumbView? = null
+        override val letterFastscrollerContainer: ViewGroup? = null
+        override val letterFastscrollerDragHandle: View? = null
         override val fragmentFastscroller: RecyclerViewFastScroller = binding.fragmentFastscroller
     }
 }

app/src/main/kotlin/org/fossify/contacts/helpers/Config.kt

@@ -18,4 +18,7 @@ class Config(context: Context) : BaseConfig(context) {
         set(autoBackupContactSources) = prefs.edit().remove(AUTO_BACKUP_CONTACT_SOURCES).putStringSet(AUTO_BACKUP_CONTACT_SOURCES, autoBackupContactSources)
             .apply()
 
+    var sidebarYOffset: Float
+        get() = prefs.getFloat(SIDEBAR_Y_OFFSET, 0f)
+        set(sidebarYOffset) = prefs.edit().putFloat(SIDEBAR_Y_OFFSET, sidebarYOffset).apply()
 }

app/src/main/kotlin/org/fossify/contacts/helpers/Constants.kt

@@ -17,6 +17,7 @@ const val AUTOMATIC_BACKUP_REQUEST_CODE = 10001
 const val AUTO_BACKUP_INTERVAL_IN_DAYS = 1
 
 const val AUTO_BACKUP_CONTACT_SOURCES = "auto_backup_contact_sources"
+const val SIDEBAR_Y_OFFSET = "sidebar_y_offset"
 
 // extras used at third party intents
 const val KEY_NAME = "name"

app/src/main/res/drawable/ic_dot.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M12,12m-3,0a3,3 0,1 1,6 0a3,3 0,1 1,-6 0" />
+</vector>

app/src/main/res/layout/fragment_letters_layout.xml

@@ -45,22 +45,41 @@
             android:paddingBottom="@dimen/secondary_fab_bottom_margin"
             app:layoutManager="org.fossify.commons.views.MyLinearLayoutManager" />
 
-        <com.reddit.indicatorfastscroll.FastScrollerView
-            android:id="@+id/letter_fastscroller"
-            android:layout_width="32dp"
+        <LinearLayout
+            android:id="@+id/letter_fastscroller_container"
+            android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_alignParentEnd="true"
-            android:paddingTop="@dimen/big_margin"
-            android:paddingBottom="@dimen/big_margin" />
+            android:gravity="center_horizontal"
+            android:orientation="vertical">
+
+            <com.reddit.indicatorfastscroll.FastScrollerView
+                android:id="@+id/letter_fastscroller"
+                android:layout_width="32dp"
+                android:layout_height="wrap_content"
+                android:paddingTop="@dimen/normal_margin"
+                android:paddingBottom="@dimen/normal_margin" />
+
+            <ImageView
+                android:id="@+id/letter_fastscroller_drag_handle"
+                android:layout_width="32dp"
+                android:layout_height="32dp"
+                android:contentDescription="@null"
+                android:padding="4dp"
+                android:src="@drawable/ic_dot" />
+
+        </LinearLayout>
 
         <com.reddit.indicatorfastscroll.FastScrollerThumbView
             android:id="@+id/letter_fastscroller_thumb"
             android:layout_width="@dimen/fab_size"
-            android:layout_height="match_parent"
-            android:layout_alignTop="@+id/letter_fastscroller"
-            android:layout_alignBottom="@+id/letter_fastscroller"
+            android:layout_height="@dimen/fab_size"
+            android:layout_alignTop="@+id/letter_fastscroller_container"
+            android:layout_alignBottom="@+id/letter_fastscroller_container"
+            android:layout_centerVertical="true"
             android:layout_marginEnd="@dimen/activity_margin"
-            android:layout_toStartOf="@+id/letter_fastscroller" />
+            android:layout_toStartOf="@+id/letter_fastscroller_container"
+            android:padding="@dimen/small_margin" />
 
     </RelativeLayout>