Working with slide backgrounds
Extracting information about all slide backgrounds
The API allows you to extract information about all the slide backgrounds in a PowerPoint document as shown in the following code sample using method getBackgroundImage() of PresentationSlide.getImageFillFormat().
advanced_usage.add_watermarks_to_presentations.PresentationGetSlideBackgroundsInformation
PresentationLoadOptions loadOptions = new PresentationLoadOptions();
// Constants.InPresentationPptx is an absolute or relative path to your document. Ex: "C:\\Docs\\presentation.pptx"
Watermarker watermarker = new Watermarker(Constants.InPresentationPptx, loadOptions);
PresentationContent content = watermarker.getContent(PresentationContent.class);
for (PresentationSlide slide : content.getSlides())
{
if (slide.getImageFillFormat().getBackgroundImage() != null)
{
System.out.println(slide.getImageFillFormat().getBackgroundImage().getWidth());
System.out.println(slide.getImageFillFormat().getBackgroundImage().getHeight());
System.out.println(slide.getImageFillFormat().getBackgroundImage().getBytes().length);
}
}
watermarker.close();
Removing a particular background
Following code sample shows how to remove the background image of a particular slide calling the method setBackgroundImage() with null.
advanced_usage.add_watermarks_to_presentations.PresentationRemoveSlideBackground
PresentationLoadOptions loadOptions = new PresentationLoadOptions();
// Constants.InPresentationPptx is an absolute or relative path to your document. Ex: "C:\\Docs\\presentation.pptx"
Watermarker watermarker = new Watermarker(Constants.InPresentationPptx, loadOptions);
PresentationContent content = watermarker.getContent(PresentationContent.class);
content.getSlides().get_Item(0).getImageFillFormat().setBackgroundImage(null);
watermarker.save(Constants.OutPresentationPptx);
watermarker.close();
Adding watermark to all background Images
Using GroupDocs.Watermark, you can also add watermark to the background images that belong to a PowerPoint document as shown in the following code sample.
advanced_usage.add_watermarks_to_presentations.PresentationAddWatermarkToSlideBackgroundImages
PresentationLoadOptions loadOptions = new PresentationLoadOptions();
// Constants.InPresentationPptx is an absolute or relative path to your document. Ex: "C:\\Docs\\presentation.pptx"
Watermarker watermarker = new Watermarker(Constants.InPresentationPptx, loadOptions);
// Initialize image or text watermark
TextWatermark watermark = new TextWatermark("Protected image", new Font("Arial", 8));
watermark.setHorizontalAlignment(HorizontalAlignment.Center);
watermark.setVerticalAlignment(VerticalAlignment.Center);
watermark.setRotateAngle(45);
watermark.setSizingType(SizingType.ScaleToParentDimensions);
watermark.setScaleFactor(1);
PresentationContent content = watermarker.getContent(PresentationContent.class);
for (PresentationSlide slide : content.getSlides())
{
if (slide.getImageFillFormat().getBackgroundImage() != null)
{
// Add watermark to the image
slide.getImageFillFormat().getBackgroundImage().add(watermark);
}
}
watermarker.save(Constants.OutPresentationPptx);
watermarker.close();
Additional settings for slide background image
GroupDocs.Watermark for Java also provides the feature that allows you to tile the picture across slide’s background. You can also make the image semi-transparent. Following code sample serves this purpose.
advanced_usage.add_watermarks_to_presentations.PresentationSetTiledSemitransparentBackground
PresentationLoadOptions loadOptions = new PresentationLoadOptions();
// Constants.InPresentationPptx is an absolute or relative path to your document. Ex: "C:\\Docs\\presentation.pptx"
Watermarker watermarker = new Watermarker(Constants.InPresentationPptx, loadOptions);
PresentationContent content = watermarker.getContent(PresentationContent.class);
PresentationSlide slide = content.getSlides().get_Item(0);
File imageFile = new File(Constants.BackgroundPng);
byte[] imageBytes = new byte[(int) imageFile.length()];
InputStream imageInputStream = new FileInputStream(imageFile);
imageInputStream.read(imageBytes);
imageInputStream.close();
slide.getImageFillFormat().setBackgroundImage(new PresentationWatermarkableImage(imageBytes));
slide.getImageFillFormat().setTileAsTexture(true);
slide.getImageFillFormat().setTransparency(0.5);
watermarker.save(Constants.OutPresentationPptx);
watermarker.close();
Settings background image for charts
GroupDocs.Watermark for Java also allows you to set the background image for a chart inside PowerPoint document using getCharts() method. You can use following code sample to achieve this functionality.
advanced_usage.add_watermarks_to_presentations.PresentationSetBackgroundImageForChart
PresentationLoadOptions loadOptions = new PresentationLoadOptions();
// Constants.InPresentationPptx is an absolute or relative path to your document. Ex: "C:\\Docs\\presentation.pptx"
Watermarker watermarker = new Watermarker(Constants.InPresentationPptx, loadOptions);
PresentationContent content = watermarker.getContent(PresentationContent.class);
File imageFile = new File(Constants.TestPng);
byte[] imageBytes = new byte[(int) imageFile.length()];
InputStream imageInputStream = new FileInputStream(imageFile);
imageInputStream.read(imageBytes);
imageInputStream.close();
content.getSlides().get_Item(0).getCharts().get_Item(0).getImageFillFormat().setBackgroundImage(new PresentationWatermarkableImage(imageBytes));
content.getSlides().get_Item(0).getCharts().get_Item(0).getImageFillFormat().setTransparency(0.5);
content.getSlides().get_Item(0).getCharts().get_Item(0).getImageFillFormat().setTileAsTexture(true);
watermarker.save(Constants.OutPresentationPptx);
watermarker.close();
More resources
GitHub examples
You may easily run the code above and see the feature in action in our GitHub examples:
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