From 9ec4364750fb1345af4fcb5a9e74682291921b2f Mon Sep 17 00:00:00 2001
From: MAEDA Go <maeda@farend.jp>
Date: Wed, 18 Feb 2026 12:58:32 +0900
Subject: [PATCH] Show PDF preview for repository files and attachments

Patch by Gregor Schmidt (user:schmidt).
---
 app/assets/stylesheets/application.css        |  2 ++
 app/assets/stylesheets/scm.css                | 30 +++++++++++++++++++
 app/controllers/attachments_controller.rb     |  2 ++
 app/views/attachments/pdf.html.erb            |  4 +++
 app/views/common/_pdf.html.erb                |  8 +++++
 app/views/repositories/entry.html.erb         |  2 ++
 config/locales/en.yml                         |  1 +
 .../functional/attachments_controller_test.rb | 11 +++++++
 8 files changed, 60 insertions(+)
 create mode 100644 app/views/attachments/pdf.html.erb
 create mode 100644 app/views/common/_pdf.html.erb

diff --git a/app/assets/stylesheets/application.css b/app/assets/stylesheets/application.css
index 3c01a73ff..0b4838dce 100644
--- a/app/assets/stylesheets/application.css
+++ b/app/assets/stylesheets/application.css
@@ -2435,6 +2435,8 @@ img {
   box-shadow: 0 1px 2px rgba(var(--oc-gray-9-rgb), 0.05);
 }
 
+.pdf-full-view-link { margin: 0 0 0.5em; }
+
 /* tablesort */
 th[role=columnheader]:not(.no-sort) {
 	cursor: pointer;
diff --git a/app/assets/stylesheets/scm.css b/app/assets/stylesheets/scm.css
index 23cc99dd3..be6058bcf 100644
--- a/app/assets/stylesheets/scm.css
+++ b/app/assets/stylesheets/scm.css
@@ -102,6 +102,36 @@ table.filecontent tr:target td.line-code { background-color:var(--oc-blue-0); }
 
 img.filecontent, video.filecontent { max-inline-size: 100%; }
 
+.filecontent.pdf {
+    inline-size: 100%;
+    max-block-size: 80vh;
+    overflow: hidden;
+    position: relative;
+}
+
+.filecontent.pdf::before {
+    content: " ";
+    display: block;
+    inline-size: 100%;
+    padding-block-end: 100%;
+}
+
+.filecontent.pdf object,
+.filecontent.pdf iframe,
+.filecontent.pdf p {
+    position: absolute;
+    inset-block-start: 0;
+    inset-inline-start: 0;
+    inset-inline-end: 0;
+}
+
+.filecontent.pdf iframe,
+.filecontent.pdf object {
+    border: none;
+    inline-size: 100%;
+    block-size: 100%;
+}
+
 .previous-filename {
   font-weight: normal;
 }
diff --git a/app/controllers/attachments_controller.rb b/app/controllers/attachments_controller.rb
index 90c3c7070..18795891d 100644
--- a/app/controllers/attachments_controller.rb
+++ b/app/controllers/attachments_controller.rb
@@ -61,6 +61,8 @@ class AttachmentsController < ApplicationController
           render :action => 'file'
         elsif @attachment.is_image?
           render :action => 'image'
+        elsif @attachment.is_pdf?
+          render :action => 'pdf'
         else
           render :action => 'other'
         end
diff --git a/app/views/attachments/pdf.html.erb b/app/views/attachments/pdf.html.erb
new file mode 100644
index 000000000..441e6155c
--- /dev/null
+++ b/app/views/attachments/pdf.html.erb
@@ -0,0 +1,4 @@
+<%= render :layout => 'layouts/file' do %>
+  <%= render :partial => 'common/pdf',
+             :locals => {:path => download_named_attachment_path(@attachment, @attachment.filename)} %>
+<% end %>
diff --git a/app/views/common/_pdf.html.erb b/app/views/common/_pdf.html.erb
new file mode 100644
index 000000000..1e8ba4866
--- /dev/null
+++ b/app/views/common/_pdf.html.erb
@@ -0,0 +1,8 @@
+<p class="pdf-full-view-link">
+  <%= link_to l(:label_open_in_full_view, :default => l(:button_download)), path %>
+</p>
+<div class="filecontent pdf">
+  <object data="<%= path %>" type="application/pdf">
+    <%= render :partial => 'common/other' %>
+  </object>
+</div>
diff --git a/app/views/repositories/entry.html.erb b/app/views/repositories/entry.html.erb
index b4a221af9..66c2154b9 100644
--- a/app/views/repositories/entry.html.erb
+++ b/app/views/repositories/entry.html.erb
@@ -10,6 +10,8 @@
 
 <% if Redmine::MimeType.is_type?('image', @path) %>
   <%= render :partial => 'common/image', :locals => {:path => @raw_url, :alt => @path} %>
+<% elsif Redmine::MimeType.of(@path) == 'application/pdf' %>
+  <%= render :partial => 'common/pdf', :locals => {:path => @raw_url} %>
 <% elsif Redmine::MimeType.of(@path) == 'text/x-textile' %>
   <%= render :partial => 'common/markup', :locals => {:markup_text_formatting => 'textile', :markup_text => @content} %>
 <% elsif Redmine::MimeType.of(@path) == 'text/markdown' %>
diff --git a/config/locales/en.yml b/config/locales/en.yml
index e99f01f74..b9d82807f 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -726,6 +726,7 @@ en:
   label_no_preview: No preview available
   label_no_preview_alternative_html: No preview available. %{link} the file instead.
   label_no_preview_download: Download
+  label_open_in_full_view: Open in full view
   label_change_status: Change status
   label_history: History
   label_attachment: File
diff --git a/test/functional/attachments_controller_test.rb b/test/functional/attachments_controller_test.rb
index 7d856b11d..bc664cea5 100644
--- a/test/functional/attachments_controller_test.rb
+++ b/test/functional/attachments_controller_test.rb
@@ -239,6 +239,17 @@ class AttachmentsControllerTest < Redmine::ControllerTest
     assert_select 'img.filecontent', :src => attachments(:attachments_010).filename
   end
 
+  def test_show_pdf
+    @request.session[:user_id] = 2
+    get(:show, :params => {:id => 23})
+    assert_response :success
+    assert_equal 'text/html', @response.media_type
+
+    path = download_named_attachment_path(attachments(:attachments_023), attachments(:attachments_023).filename)
+    assert_select ".filecontent.pdf object[data='#{path}']"
+    assert_select '.nodata', :text => 'No preview available'
+  end
+
   def test_show_other_with_no_preview
     @request.session[:user_id] = 2
     get(:show, :params => {:id => 6})
-- 
2.50.1