Add bookmarks so we can find a location after reflowing a document.

4 files changed, 57 insertions, 2 deletions

diff --git a/platform/java/example/Viewer.java b/platform/java/example/Viewer.java
index 1361a538..a924cf4b 100644
--- a/platform/java/example/Viewer.java
+++ b/platform/java/example/Viewer.java
@@ -383,12 +383,12 @@ public class Viewer extends Frame implements WindowListener, ActionListener, Ite
 		}
 
 		if (layoutEm != oldLayoutEm) {
-			float oldPos = (pageNumber + 0.5f) / (float)pageCount;
+			long mark = doc.makeBookmark(pageNumber);
 			doc.layout(layoutWidth, layoutHeight, layoutEm);
 			updateOutline();
 			pageCount = doc.countPages();
 			pageLabel.setText("/ " + pageCount);
-			pageNumber = (int)(oldPos * pageCount);
+			pageNumber = doc.findBookmark(mark);
 		}
 
 		if (zoomLevel != oldZoomLevel || pageNumber != oldPageNumber || layoutEm != oldLayoutEm || searchHits != oldSearchHits)
diff --git a/platform/java/mupdf_native.c b/platform/java/mupdf_native.c
index cbb3dd7a..aec932c4 100644
--- a/platform/java/mupdf_native.c
+++ b/platform/java/mupdf_native.c
@@ -4222,6 +4222,42 @@ FUN(Document_loadOutline)(JNIEnv *env, jobject self)
 	return joutline;
 }
 
+JNIEXPORT jlong JNICALL
+FUN(Document_makeBookmark)(JNIEnv *env, jobject self, jint page)
+{
+	fz_context *ctx = get_context(env);
+	fz_document *doc = from_Document(env, self);
+	fz_bookmark mark = 0;
+
+	fz_try(ctx)
+		mark = fz_make_bookmark(ctx, doc, page);
+	fz_catch(ctx)
+	{
+		jni_rethrow(env, ctx);
+		return 0;
+	}
+
+	return mark;
+}
+
+JNIEXPORT jint JNICALL
+FUN(Document_findBookmark)(JNIEnv *env, jobject self, jlong mark)
+{
+	fz_context *ctx = get_context(env);
+	fz_document *doc = from_Document(env, self);
+	int page = -1;
+
+	fz_try(ctx)
+		page = fz_lookup_bookmark(ctx, doc, mark);
+	fz_catch(ctx)
+	{
+		jni_rethrow(env, ctx);
+		return -1;
+	}
+
+	return page;
+}
+
 JNIEXPORT jobject JNICALL
 FUN(Document_toPDFDocument)(JNIEnv *env, jobject self)
 {
diff --git a/platform/java/mupdf_native.h b/platform/java/mupdf_native.h
index 3e6c51b3..8b0b2fe3 100644
--- a/platform/java/mupdf_native.h
+++ b/platform/java/mupdf_native.h
@@ -683,6 +683,22 @@ JNIEXPORT void JNICALL Java_com_artifex_mupdf_fitz_Document_layout
 
 /*
  * Class:     com_artifex_mupdf_fitz_Document
+ * Method:    makeBookmark
+ * Signature: (I)J
+ */
+JNIEXPORT jlong JNICALL Java_com_artifex_mupdf_fitz_Document_makeBookmark
+  (JNIEnv *, jobject, jint);
+
+/*
+ * Class:     com_artifex_mupdf_fitz_Document
+ * Method:    findBookmark
+ * Signature: (J)I
+ */
+JNIEXPORT jint JNICALL Java_com_artifex_mupdf_fitz_Document_findBookmark
+  (JNIEnv *, jobject, jlong);
+
+/*
+ * Class:     com_artifex_mupdf_fitz_Document
  * Method:    isUnencryptedPDF
  * Signature: ()Z
  */
diff --git a/platform/java/src/com/artifex/mupdf/fitz/Document.java b/platform/java/src/com/artifex/mupdf/fitz/Document.java
index 29cad4db..1fc21c13 100644
--- a/platform/java/src/com/artifex/mupdf/fitz/Document.java
+++ b/platform/java/src/com/artifex/mupdf/fitz/Document.java
@@ -49,6 +49,9 @@ public class Document
 	public native boolean isReflowable();
 	public native void layout(float width, float height, float em);
 
+	public native long makeBookmark(int page);
+	public native int findBookmark(long mark);
+
 	public native boolean isUnencryptedPDF();
 
 	public native PDFDocument toPDFDocument();