Disable refresh if not at the top, resolves #1450

6 files changed, 89 insertions, 8 deletions

diff --git a/app/src/main/kotlin/com/pitchedapps/frost/activities/LoginActivity.kt b/app/src/main/kotlin/com/pitchedapps/frost/activities/LoginActivity.kt
index ed207896..42a0f6bb 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/activities/LoginActivity.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/activities/LoginActivity.kt
@@ -87,6 +87,9 @@ class LoginActivity : BaseActivity() {
             toolbar(toolbar)
         }
         profileLoader = GlideApp.with(profile)
+        swipeRefresh.setOnChildScrollUpCallback { parent, child ->
+            web.canScrollVertically(-1)
+        }
         launch {
             for (refreshing in refreshChannel.uniqueOnly(this)) {
                 if (refreshing) swipeRefresh.isEnabled = true
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/views/SwipeRefreshLayout.kt b/app/src/main/kotlin/com/pitchedapps/frost/views/SwipeRefreshLayout.kt
new file mode 100644
index 00000000..0ab11fc6
--- /dev/null
+++ b/app/src/main/kotlin/com/pitchedapps/frost/views/SwipeRefreshLayout.kt
@@ -0,0 +1,78 @@
+package com.pitchedapps.frost.views
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.MotionEvent
+import android.view.View
+import android.view.ViewConfiguration
+import android.webkit.WebView
+import android.widget.ListView
+import androidx.core.widget.ListViewCompat
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout.OnChildScrollUpCallback
+import com.pitchedapps.frost.utils.L
+
+/**
+ * Variant that forbids refreshing if child layout is not at the top
+ * Inspired by https://github.com/slapperwan/gh4a/blob/master/app/src/main/java/com/gh4a/widget/SwipeRefreshLayout.java
+ *
+ */
+class SwipeRefreshLayout @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null) :
+    SwipeRefreshLayout(context, attrs) {
+
+    private var preventRefresh: Boolean = false
+    private var downY: Float = -1f
+    private val touchSlop = ViewConfiguration.get(context).scaledTouchSlop
+
+    /**
+     * Copy of [canChildScrollUp], with additional support if necessary
+     */
+    private val canChildScrollUp = OnChildScrollUpCallback { parent, child ->
+        when (child) {
+            is WebView -> child.canScrollVertically(-1).apply {
+                L.d { "Webview can scroll up $this" }
+            }
+            is ListView -> ListViewCompat.canScrollList(child, -1)
+            // Supports webviews as well
+            else -> child?.canScrollVertically(-1) ?: false
+        }
+    }
+
+    init {
+        setOnChildScrollUpCallback(canChildScrollUp)
+    }
+
+    override fun onInterceptTouchEvent(ev: MotionEvent): Boolean {
+        if (ev.action != MotionEvent.ACTION_DOWN && preventRefresh) {
+            return false
+        }
+        when (ev.action) {
+            MotionEvent.ACTION_DOWN -> {
+                downY = ev.y
+                preventRefresh = canChildScrollUp()
+            }
+            MotionEvent.ACTION_MOVE -> {
+                if (downY - ev.y > touchSlop) {
+                    preventRefresh = true
+                    return false
+                }
+            }
+        }
+        return super.onInterceptTouchEvent(ev)
+    }
+
+    override fun onNestedScroll(target: View, dxConsumed: Int, dyConsumed: Int, dxUnconsumed: Int, dyUnconsumed: Int) {
+        if (preventRefresh) {
+            /*
+             * Ignoring offsetInWindow since
+             * 1. It doesn't seem to matter in the typical use case
+             * 2. It isn't being transferred to the underlying array used by the super class
+             */
+            dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, null)
+        } else {
+            super.onNestedScroll(target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed)
+        }
+    }
+
+    interface OnRefreshListener : SwipeRefreshLayout.OnRefreshListener
+}
\ No newline at end of file
diff --git a/app/src/main/res/layout/activity_debug.xml b/app/src/main/res/layout/activity_debug.xml
index 55553f42..c3818749 100644
--- a/app/src/main/res/layout/activity_debug.xml
+++ b/app/src/main/res/layout/activity_debug.xml
@@ -16,7 +16,7 @@
         app:layout_scrollFlags="scroll|enterAlways"
         app:popupTheme="@style/AppTheme.PopupOverlay" />
 
-    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+    <com.pitchedapps.frost.views.SwipeRefreshLayout
         android:id="@+id/swipe_refresh"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
@@ -29,7 +29,7 @@
             android:focusable="true"
             android:focusableInTouchMode="true" />
 
-    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+    </com.pitchedapps.frost.views.SwipeRefreshLayout>
 
     <include layout="@layout/view_main_fab" />
 
diff --git a/app/src/main/res/layout/login_webview.xml b/app/src/main/res/layout/login_webview.xml
index 8816383a..48d48589 100644
--- a/app/src/main/res/layout/login_webview.xml
+++ b/app/src/main/res/layout/login_webview.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.swiperefreshlayout.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<com.pitchedapps.frost.views.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/swipe_refresh"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
@@ -36,4 +36,4 @@
 
     </RelativeLayout>
 
-</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
\ No newline at end of file
+</com.pitchedapps.frost.views.SwipeRefreshLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/view_content_base_recycler.xml b/app/src/main/res/layout/view_content_base_recycler.xml
index 05b14215..ce33ce13 100644
--- a/app/src/main/res/layout/view_content_base_recycler.xml
+++ b/app/src/main/res/layout/view_content_base_recycler.xml
@@ -6,7 +6,7 @@
     android:layout_height="match_parent"
     app:layout_behavior="@string/appbar_scrolling_view_behavior">
 
-    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+    <com.pitchedapps.frost.views.SwipeRefreshLayout
         android:id="@id/content_refresh"
         android:layout_width="match_parent"
         android:layout_height="wrap_content">
@@ -19,7 +19,7 @@
             android:focusableInTouchMode="true"
             app:layout_behavior="@string/appbar_scrolling_view_behavior" />
 
-    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+    </com.pitchedapps.frost.views.SwipeRefreshLayout>
 
     <ProgressBar
         android:id="@id/content_progress"
diff --git a/app/src/main/res/layout/view_content_base_web.xml b/app/src/main/res/layout/view_content_base_web.xml
index 9360b9f3..641ce918 100644
--- a/app/src/main/res/layout/view_content_base_web.xml
+++ b/app/src/main/res/layout/view_content_base_web.xml
@@ -6,7 +6,7 @@
     android:layout_height="match_parent"
     app:layout_behavior="@string/appbar_scrolling_view_behavior">
 
-    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+    <com.pitchedapps.frost.views.SwipeRefreshLayout
         android:id="@id/content_refresh"
         android:layout_width="match_parent"
         android:layout_height="wrap_content">
@@ -19,7 +19,7 @@
             android:focusableInTouchMode="true"
             app:layout_behavior="@string/appbar_scrolling_view_behavior" />
 
-    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+    </com.pitchedapps.frost.views.SwipeRefreshLayout>
 
     <ProgressBar
         android:id="@id/content_progress"