From cc633589d950b9665596910eb0a0acab885a3b4e Mon Sep 17 00:00:00 2001
From: Lovell Fuller <github@lovell.info>
Date: Tue, 1 Jan 2019 22:10:27 +0000
Subject: [PATCH] Expose pages metadata for multi-page input images #1205

---
 docs/changelog.md     |  3 +++
 src/metadata.cc       | 12 ++++++++++++
 src/metadata.h        |  4 ++++
 test/unit/metadata.js | 24 ++++++++++++++++++++++++
 4 files changed, 43 insertions(+)

diff --git a/docs/changelog.md b/docs/changelog.md
index 9e538e8f..d43613a0 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -6,6 +6,9 @@ Requires libvips v8.7.0.
 
 #### v0.21.2 - TBD
 
+* Expose `pages` and `pageHeight` metadata for multi-page input images.
+  [#1205](https://github.com/lovell/sharp/issues/1205)
+
 * Prevent mutatation of options passed to `jpeg`.
   [#1516](https://github.com/lovell/sharp/issues/1516)
 
diff --git a/src/metadata.cc b/src/metadata.cc
index efd91214..2097f6fe 100644
--- a/src/metadata.cc
+++ b/src/metadata.cc
@@ -71,6 +71,12 @@ class MetadataWorker : public Nan::AsyncWorker {
       if (image.get_typeof("palette-bit-depth") == G_TYPE_INT) {
         baton->paletteBitDepth = image.get_int("palette-bit-depth");
       }
+      if (image.get_typeof(VIPS_META_N_PAGES) == G_TYPE_INT) {
+        baton->pages = image.get_int(VIPS_META_N_PAGES);
+      }
+      if (image.get_typeof(VIPS_META_PAGE_HEIGHT) == G_TYPE_INT) {
+        baton->pageHeight = image.get_int(VIPS_META_PAGE_HEIGHT);
+      }
       baton->hasProfile = sharp::HasProfile(image);
       // Derived attributes
       baton->hasAlpha = sharp::HasAlpha(image);
@@ -146,6 +152,12 @@ class MetadataWorker : public Nan::AsyncWorker {
       if (baton->paletteBitDepth > 0) {
         Set(info, New("paletteBitDepth").ToLocalChecked(), New<v8::Uint32>(baton->paletteBitDepth));
       }
+      if (baton->pages > 0) {
+        Set(info, New("pages").ToLocalChecked(), New<v8::Uint32>(baton->pages));
+      }
+      if (baton->pageHeight > 0) {
+        Set(info, New("pageHeight").ToLocalChecked(), New<v8::Uint32>(baton->pageHeight));
+      }
       Set(info, New("hasProfile").ToLocalChecked(), New<v8::Boolean>(baton->hasProfile));
       Set(info, New("hasAlpha").ToLocalChecked(), New<v8::Boolean>(baton->hasAlpha));
       if (baton->orientation > 0) {
diff --git a/src/metadata.h b/src/metadata.h
index d279e433..30ca189e 100644
--- a/src/metadata.h
+++ b/src/metadata.h
@@ -34,6 +34,8 @@ struct MetadataBaton {
   std::string chromaSubsampling;
   bool isProgressive;
   int paletteBitDepth;
+  int pages;
+  int pageHeight;
   bool hasProfile;
   bool hasAlpha;
   int orientation;
@@ -55,6 +57,8 @@ struct MetadataBaton {
     density(0),
     isProgressive(false),
     paletteBitDepth(0),
+    pages(0),
+    pageHeight(0),
     hasProfile(false),
     hasAlpha(false),
     orientation(0),
diff --git a/test/unit/metadata.js b/test/unit/metadata.js
index 6fcac1f9..fbceb32c 100644
--- a/test/unit/metadata.js
+++ b/test/unit/metadata.js
@@ -103,6 +103,30 @@ describe('Image metadata', function () {
     });
   });
 
+  it('Multipage TIFF', function (done) {
+    sharp(fixtures.inputTiffMultipage).metadata(function (err, metadata) {
+      if (err) throw err;
+      console.log(metadata);
+      assert.strictEqual('tiff', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
+      assert.strictEqual(2464, metadata.width);
+      assert.strictEqual(3248, metadata.height);
+      assert.strictEqual('b-w', metadata.space);
+      assert.strictEqual(1, metadata.channels);
+      assert.strictEqual('uchar', metadata.depth);
+      assert.strictEqual(300, metadata.density);
+      assert.strictEqual('undefined', typeof metadata.chromaSubsampling);
+      assert.strictEqual(false, metadata.isProgressive);
+      assert.strictEqual(2, metadata.pages);
+      assert.strictEqual(false, metadata.hasProfile);
+      assert.strictEqual(false, metadata.hasAlpha);
+      assert.strictEqual(1, metadata.orientation);
+      assert.strictEqual('undefined', typeof metadata.exif);
+      assert.strictEqual('undefined', typeof metadata.icc);
+      done();
+    });
+  });
+
   it('PNG', function (done) {
     sharp(fixtures.inputPng).metadata(function (err, metadata) {
       if (err) throw err;