iOS: refactor AirPrint code ready for printing at higher res and in strips

1 files changed, 113 insertions, 29 deletions

diff --git a/platform/ios/Classes/MuPrintPageRenderer.m b/platform/ios/Classes/MuPrintPageRenderer.m
index 0ab74c79..919145fd 100644
--- a/platform/ios/Classes/MuPrintPageRenderer.m
+++ b/platform/ios/Classes/MuPrintPageRenderer.m
@@ -32,59 +32,143 @@
 	return npages;
 }
 
--(void) drawPageAtIndex:(NSInteger)pageIndex inRect:(CGRect)printableRect
+static fz_page *getPage(fz_document *doc, int pageIndex)
 {
-	CGContextRef cgctx = UIGraphicsGetCurrentContext();
+	__block fz_page *page = NULL;
 
-	if (!cgctx) return;
+	dispatch_sync(queue, ^{
+		fz_try(ctx)
+		{
+			page = fz_load_page(doc, pageIndex);
+		}
+		fz_catch(ctx)
+		{
+			printf("Failed to load page\n");
+		}
+	});
 
-	CGSize paperSize = self.paperRect.size;
-	// We must perform mupdf calls within this function, but all library calls need
-	// to be on our background thread, so we run them synchronously on the queue
+	return page;
+}
+
+static CGSize getPageSize(fz_document *doc, fz_page *page)
+{
+	__block CGSize size = {0.0,0.0};
+
+	dispatch_sync(queue, ^{
+		fz_try(ctx)
+		{
+			fz_rect bounds;
+			fz_bound_page(doc, page, &bounds);
+			size.width = bounds.x1 - bounds.x0;
+			size.height = bounds.y1 - bounds.y0;
+		}
+		fz_catch(ctx)
+		{
+			printf("Failed to find page bounds\n");
+		}
+	});
 
+	return size;
+}
+
+static fz_pixmap *createPixMap(CGSize size)
+{
 	__block fz_pixmap *pix = NULL;
-	__block CGSize pageSize;
+
+	dispatch_sync(queue, ^{
+		fz_try(ctx)
+		{
+			pix = fz_new_pixmap(ctx, fz_device_rgb(ctx), size.width, size.height);
+		}
+		fz_catch(ctx)
+		{
+			printf("Failed to create pixmap\n");
+		}
+	});
+
+	return pix;
+}
+
+static void freePage(fz_document *doc, fz_page *page)
+{
+	dispatch_sync(queue, ^{
+		fz_free_page(doc, page);
+	});
+}
+
+static void dropPixmap(fz_pixmap *pix)
+{
+	dispatch_sync(queue, ^{
+		fz_drop_pixmap(ctx, pix);
+	});
+}
+static void renderPage(fz_document *doc, fz_page *page, fz_pixmap *pix, fz_matrix *ctm)
+{
 	dispatch_sync(queue, ^{
-		fz_page *page = NULL;
 		fz_device *dev = NULL;
-		fz_var(page);
 		fz_var(dev);
 		fz_try(ctx)
 		{
-			fz_rect bounds;
-			fz_matrix ctm;
-			page = fz_load_page(docRef->doc, pageIndex);
-			fz_bound_page(docRef->doc, page, &bounds);
-			pageSize.width = bounds.x1 - bounds.x0;
-			pageSize.height = bounds.y1 - bounds.y0;
-			CGSize scale = fitPageToScreen(pageSize, paperSize);
-			pageSize.width = roundf(pageSize.width * scale.width);
-			pageSize.height = roundf(pageSize.height * scale.height);
-			// Need to render upside down. No idea why.
-			fz_scale(&ctm, scale.width, -scale.height);
-			fz_pre_translate(&ctm, 0, -pageSize.height);
-			pix = fz_new_pixmap(ctx, fz_device_rgb(ctx), pageSize.width, pageSize.height);
-			fz_clear_pixmap_with_value(ctx, pix, 255);
 			dev = fz_new_draw_device(ctx, pix);
-			fz_run_page(docRef->doc, page, dev, &ctm, NULL);
+			fz_clear_pixmap_with_value(ctx, pix, 0xFF);
+			fz_run_page(doc, page, dev, ctm, NULL);
 		}
 		fz_always(ctx)
 		{
-			fz_free_page(docRef->doc, page);
 			fz_free_device(dev);
 		}
 		fz_catch(ctx)
 		{
-			printf("Failed to print page %d\n", pageIndex+1);
+			printf("Failed to render page\n");
 		}
 	});
+}
+
+-(void) drawPageAtIndex:(NSInteger)pageIndex inRect:(CGRect)printableRect
+{
+	fz_page *page = NULL;
+	fz_pixmap *pix = NULL;
+	CGDataProviderRef dataref = NULL;
+	CGImageRef img = NULL;
+	CGContextRef cgctx = UIGraphicsGetCurrentContext();
+
+	if (!cgctx) return;
+
+	CGSize paperSize = self.paperRect.size;
+	page = getPage(docRef->doc, pageIndex);
+	if (page == NULL) return;
+
+	CGSize pageSize = getPageSize(docRef->doc, page);
+	if (pageSize.width == 0.0 || pageSize.height == 0.0)
+		goto exit;
+
+	CGSize scale = fitPageToScreen(pageSize, paperSize);
+	pageSize.width = roundf(pageSize.width * scale.width);
+	pageSize.height = roundf(pageSize.height *scale.height);
+
+	pix = createPixMap(pageSize);
+	if (!pix)
+		goto exit;
 
-	if (!pix) return;
+	dataref = wrapPixmap(pix);
+	if (dataref == NULL)
+		goto exit;
+
+	img = newCGImageWithPixmap(pix, dataref);
+	if (img == NULL)
+		goto exit;
+
+	fz_matrix ctm;
+	fz_scale(&ctm, scale.width, -scale.height);
+	fz_pre_translate(&ctm, 0, -pageSize.height);
+
+	renderPage(docRef->doc, page, pix, &ctm);
 
 	CGRect rect = {{0.0,0.0},pageSize};
-	CGDataProviderRef dataref = wrapPixmap(pix);
-	CGImageRef img = newCGImageWithPixmap(pix, dataref);
 	CGContextDrawImage(cgctx, rect, img);
+
+exit:
+	freePage(docRef->doc, page);
 	CGImageRelease(img);
 	CGDataProviderRelease(dataref); //releases pix
 }