fix(file-detail): better spacing

app/src/main/java/com/nextcloud/ui/fileDetail/FileDetailPreview.kt

@@ -10,6 +10,7 @@ package com.nextcloud.ui.fileDetail
 import android.graphics.Bitmap
 import android.graphics.drawable.Drawable
 import android.widget.ImageView
+import com.nextcloud.utils.extensions.getBigThumbnail
 import com.nextcloud.utils.extensions.getSmallThumbnail
 import com.nextcloud.utils.thumbnail.FolderThumbnailGenerator
 import com.nextcloud.utils.thumbnail.VideoOverlayGenerator
@@ -32,7 +33,7 @@ class FileDetailPreview(
             return
         }
 
-        val thumbnail = file.getSmallThumbnail()
+        val thumbnail = file.getBigThumbnail() ?: file.getSmallThumbnail()
         if (thumbnail == null) {
             setIcon(MimeTypeUtil.getFileTypeIcon(file.mimeType, file.fileName, toolbarActivity, viewThemeUtils))
         } else {
@@ -53,7 +54,7 @@ class FileDetailPreview(
 
     private fun setIcon(icon: Drawable) {
         previewImageView?.setImageDrawable(icon)
-        val padding = toolbarActivity.resources.getDimensionPixelSize(R.dimen.standard_double_padding)
+        val padding = toolbarActivity.resources.getDimensionPixelSize(R.dimen.file_details_preview_icon_padding)
         applyScaling(ImageView.ScaleType.FIT_CENTER, padding)
     }
 

app/src/main/java/com/nextcloud/ui/fileDetail/HeaderFirstNestedScrollView.kt

@@ -0,0 +1,33 @@
+/*
+ * Nextcloud - Android Client
+ *
+ * SPDX-FileCopyrightText: 2026 Alper Ozturk <alper.ozturk@nextcloud.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+package com.nextcloud.ui.fileDetail
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.View
+import androidx.core.widget.NestedScrollView
+
+class HeaderFirstNestedScrollView @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyleAttr: Int = 0
+) : NestedScrollView(context, attrs, defStyleAttr) {
+
+    override fun onNestedPreScroll(target: View, dx: Int, dy: Int, consumed: IntArray, type: Int) {
+        super.onNestedPreScroll(target, dx, dy, consumed, type)
+
+        val remainingDy = dy - consumed[1]
+        if (remainingDy <= 0) {
+            return
+        }
+
+        val scrollYBefore = scrollY
+        scrollBy(0, remainingDy)
+        consumed[1] += scrollY - scrollYBefore
+    }
+}

app/src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.kt

@@ -2065,7 +2065,7 @@ class FileDisplayActivity :
         setLeftFragment(detailFragment, false)
         // swap now, so no frame shows the list without its sort row
         supportFragmentManager.executePendingTransactions()
-        configureToolbarForPreview(file)
+        updateActionBarForFile(file)
     }
 
     /**

app/src/main/java/com/owncloud/android/ui/activity/ToolbarActivity.java

@@ -15,7 +15,6 @@
 
 import android.animation.AnimatorInflater;
 import android.annotation.SuppressLint;
-import android.graphics.Color;
 import android.view.View;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
@@ -347,13 +346,7 @@ public final void hideInfoBox() {
     }
 
     public void setPreviewImageVisibility(boolean isVisibility) {
-        if (mPreviewImage != null && mPreviewImageContainer != null) {
-            if (isVisibility) {
-                mToolbar.setTitle(null);
-                mToolbar.setBackgroundColor(Color.TRANSPARENT);
-            } else {
-                mToolbar.setBackgroundResource(R.color.appbar);
-            }
+        if (mPreviewImageContainer != null) {
             mPreviewImageContainer.setVisibility(isVisibility ? View.VISIBLE : View.GONE);
         }
     }

app/src/main/java/com/owncloud/android/ui/fragment/FileDetailFragment.java

@@ -241,6 +241,8 @@ public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
 
         binding = FileDetailsFragmentBinding.inflate(inflater, container, false);
         view = binding.getRoot();
+        binding.detailContainer.addOnLayoutChangeListener((v, left, top, right, bottom, oldLeft, oldTop, oldRight,
+                                                           oldBottom) -> fitTabContentToViewport());
 
         if (getFile() == null || user == null) {
             showEmptyContent();
@@ -843,6 +845,27 @@ public void showHideFragmentView(boolean isFragmentReplaced) {
         binding.sharingFrameContainer.setVisibility(isFragmentReplaced ? View.VISIBLE : View.GONE);
     }
 
+    private void fitTabContentToViewport() {
+        int tabLayoutHeight = binding.tabLayout.getVisibility() == View.VISIBLE ? binding.tabLayout.getHeight() : 0;
+        int tabContentHeight = binding.detailContainer.getHeight() - tabLayoutHeight;
+        if (tabContentHeight <= 0) {
+            return;
+        }
+
+        setHeight(binding.pager, tabContentHeight);
+        setHeight(binding.sharingFrameContainer, tabContentHeight);
+    }
+
+    private void setHeight(View target, int height) {
+        ViewGroup.LayoutParams params = target.getLayoutParams();
+        if (params.height == height) {
+            return;
+        }
+
+        params.height = height;
+        target.post(target::requestLayout);
+    }
+
     /**
      * open the new sharing screen process to modify the created share
      *