Save to a PDF file should look like print preview.

When rendering a PDF file for print preview we take into account
the selected print options such as paper size, orientation, etc
without modifying the document. To print we send the doc in its
original form and the print options so the print service can apply
the necessary transforms in addition to the optional custom options
it supports. When saving to PDF we have to actually change the
document as we act as a print service.

bug:13545980

Change-Id: Icdcecf962bec6ff742cc6015df5af9d9086ce760

1 files changed, 202 insertions, 2 deletions

diff --git a/core/jni/android/graphics/pdf/PdfEditor.cpp b/core/jni/android/graphics/pdf/PdfEditor.cpp
index 5f60c9e..2b756e2 100644
--- a/core/jni/android/graphics/pdf/PdfEditor.cpp
+++ b/core/jni/android/graphics/pdf/PdfEditor.cpp
@@ -19,6 +19,9 @@
 #include "fpdfview.h"
 #include "fpdfedit.h"
 #include "fpdfsave.h"
+#include "fsdk_rendercontext.h"
+#include "fpdf_transformpage.h"
+#include "SkMatrix.h"
 
 #include <android_runtime/AndroidRuntime.h>
 #include <vector>
@@ -29,6 +32,20 @@
 
 namespace android {
 
+enum PageBox {PAGE_BOX_MEDIA, PAGE_BOX_CROP};
+
+static struct {
+    jfieldID x;
+    jfieldID y;
+} gPointClassInfo;
+
+static struct {
+    jfieldID left;
+    jfieldID top;
+    jfieldID right;
+    jfieldID bottom;
+} gRectClassInfo;
+
 static Mutex sLock;
 
 static int sUnmatchedInitRequestCount = 0;
@@ -144,18 +161,201 @@ static void nativeWrite(JNIEnv* env, jclass thiz, jlong documentPtr, jint fd) {
     }
 }
 
+static void nativeSetTransformAndClip(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
+        jlong transformPtr, jint clipLeft, jint clipTop, jint clipRight, jint clipBottom) {
+    FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);
+
+    CPDF_Page* page = (CPDF_Page*) FPDF_LoadPage(document, pageIndex);
+    if (!page) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+                "cannot open page");
+        return;
+    }
+
+    double width = 0;
+    double height = 0;
+
+    const int result = FPDF_GetPageSizeByIndex(document, pageIndex, &width, &height);
+    if (!result) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+                    "cannot get page size");
+        return;
+    }
+
+    CFX_AffineMatrix matrix;
+
+    SkMatrix* skTransform = reinterpret_cast<SkMatrix*>(transformPtr);
+
+    SkScalar transformValues[6];
+    skTransform->asAffine(transformValues);
+
+    // PDF's coordinate system origin is left-bottom while in graphics it
+    // is the top-left. So, translate the PDF coordinates to ours.
+    matrix.Set(1, 0, 0, -1, 0, page->GetPageHeight());
+
+    // Apply the transformation what was created in our coordinates.
+    matrix.Concat(transformValues[SkMatrix::kAScaleX], transformValues[SkMatrix::kASkewY],
+            transformValues[SkMatrix::kASkewX], transformValues[SkMatrix::kAScaleY],
+            transformValues[SkMatrix::kATransX], transformValues[SkMatrix::kATransY]);
+
+    // Translate the result back to PDF coordinates.
+    matrix.Concat(1, 0, 0, -1, 0, page->GetPageHeight());
+
+    FS_MATRIX transform = {matrix.a, matrix.b, matrix.c, matrix.d, matrix.e, matrix.f};
+    FS_RECTF clip = {(float) clipLeft, (float) clipTop, (float) clipRight, (float) clipBottom};
+
+    FPDFPage_TransFormWithClip(page, &transform, &clip);
+
+    FPDF_ClosePage(page);
+}
+
+static void nativeGetPageSize(JNIEnv* env, jclass thiz, jlong documentPtr,
+        jint pageIndex, jobject outSize) {
+    FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);
+
+    FPDF_PAGE page = FPDF_LoadPage(document, pageIndex);
+    if (!page) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+                "cannot open page");
+        return;
+    }
+
+    double width = 0;
+    double height = 0;
+
+    const int result = FPDF_GetPageSizeByIndex(document, pageIndex, &width, &height);
+    if (!result) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+                    "cannot get page size");
+        return;
+    }
+
+    env->SetIntField(outSize, gPointClassInfo.x, width);
+    env->SetIntField(outSize, gPointClassInfo.y, height);
+
+    FPDF_ClosePage(page);
+}
+
+static jboolean nativeScaleForPrinting(JNIEnv* env, jclass thiz, jlong documentPtr) {
+    FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);
+    FPDF_BOOL success = FPDF_VIEWERREF_GetPrintScaling(document);
+    return success ? JNI_TRUE : JNI_FALSE;
+}
+
+static bool nativeGetPageBox(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
+        PageBox pageBox, jobject outBox) {
+    FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);
+
+    FPDF_PAGE page = FPDF_LoadPage(document, pageIndex);
+    if (!page) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+                "cannot open page");
+        return false;
+    }
+
+    float left;
+    float top;
+    float right;
+    float bottom;
+
+    const FPDF_BOOL success = (pageBox == PAGE_BOX_MEDIA)
+        ? FPDFPage_GetMediaBox(page, &left, &top, &right, &bottom)
+        : FPDFPage_GetCropBox(page, &left, &top, &right, &bottom);
+
+    FPDF_ClosePage(page);
+
+    if (!success) {
+        return false;
+    }
+
+    env->SetIntField(outBox, gRectClassInfo.left, (int) left);
+    env->SetIntField(outBox, gRectClassInfo.top, (int) top);
+    env->SetIntField(outBox, gRectClassInfo.right, (int) right);
+    env->SetIntField(outBox, gRectClassInfo.bottom, (int) bottom);
+
+    return true;
+}
+
+static jboolean nativeGetPageMediaBox(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
+        jobject outMediaBox) {
+    const bool success = nativeGetPageBox(env, thiz, documentPtr, pageIndex, PAGE_BOX_MEDIA,
+            outMediaBox);
+    return success ? JNI_TRUE : JNI_FALSE;
+}
+
+static jboolean nativeGetPageCropBox(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
+        jobject outMediaBox) {
+    const bool success = nativeGetPageBox(env, thiz, documentPtr, pageIndex, PAGE_BOX_CROP,
+         outMediaBox);
+    return success ? JNI_TRUE : JNI_FALSE;
+}
+
+static void nativeSetPageBox(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
+        PageBox pageBox, jobject box) {
+    FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);
+
+    FPDF_PAGE page = FPDF_LoadPage(document, pageIndex);
+    if (!page) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+                "cannot open page");
+        return;
+    }
+
+    const int left = env->GetIntField(box, gRectClassInfo.left);
+    const int top = env->GetIntField(box, gRectClassInfo.top);
+    const int right = env->GetIntField(box, gRectClassInfo.right);
+    const int bottom = env->GetIntField(box, gRectClassInfo.bottom);
+
+    if (pageBox == PAGE_BOX_MEDIA) {
+        FPDFPage_SetMediaBox(page, left, top, right, bottom);
+    } else {
+        FPDFPage_SetCropBox(page, left, top, right, bottom);
+    }
+
+    FPDF_ClosePage(page);
+}
+
+static void nativeSetPageMediaBox(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
+        jobject mediaBox) {
+    nativeSetPageBox(env, thiz, documentPtr, pageIndex, PAGE_BOX_MEDIA, mediaBox);
+}
+
+static void nativeSetPageCropBox(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
+        jobject mediaBox) {
+    nativeSetPageBox(env, thiz, documentPtr, pageIndex, PAGE_BOX_CROP, mediaBox);
+}
+
 static JNINativeMethod gPdfEditor_Methods[] = {
     {"nativeOpen", "(IJ)J", (void*) nativeOpen},
     {"nativeClose", "(J)V", (void*) nativeClose},
     {"nativeGetPageCount", "(J)I", (void*) nativeGetPageCount},
     {"nativeRemovePage", "(JI)I", (void*) nativeRemovePage},
-    {"nativeWrite", "(JI)V", (void*) nativeWrite}
+    {"nativeWrite", "(JI)V", (void*) nativeWrite},
+    {"nativeSetTransformAndClip", "(JIJIIII)V", (void*) nativeSetTransformAndClip},
+    {"nativeGetPageSize", "(JILandroid/graphics/Point;)V", (void*) nativeGetPageSize},
+    {"nativeScaleForPrinting", "(J)Z", (void*) nativeScaleForPrinting},
+    {"nativeGetPageMediaBox", "(JILandroid/graphics/Rect;)Z", (void*) nativeGetPageMediaBox},
+    {"nativeSetPageMediaBox", "(JILandroid/graphics/Rect;)V", (void*) nativeSetPageMediaBox},
+    {"nativeGetPageCropBox", "(JILandroid/graphics/Rect;)Z", (void*) nativeGetPageCropBox},
+    {"nativeSetPageCropBox", "(JILandroid/graphics/Rect;)V", (void*) nativeSetPageCropBox}
 };
 
 int register_android_graphics_pdf_PdfEditor(JNIEnv* env) {
-    return android::AndroidRuntime::registerNativeMethods(
+    const int result = android::AndroidRuntime::registerNativeMethods(
             env, "android/graphics/pdf/PdfEditor", gPdfEditor_Methods,
             NELEM(gPdfEditor_Methods));
+
+    jclass pointClass = env->FindClass("android/graphics/Point");
+    gPointClassInfo.x = env->GetFieldID(pointClass, "x", "I");
+    gPointClassInfo.y = env->GetFieldID(pointClass, "y", "I");
+
+    jclass rectClass = env->FindClass("android/graphics/Rect");
+    gRectClassInfo.left = env->GetFieldID(rectClass, "left", "I");
+    gRectClassInfo.top = env->GetFieldID(rectClass, "top", "I");
+    gRectClassInfo.right = env->GetFieldID(rectClass, "right", "I");
+    gRectClassInfo.bottom = env->GetFieldID(rectClass, "bottom", "I");
+
+    return result;
 };
 
 };