Size and position page elements

Page Summary

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• Page elements can be sized and positioned using getter/setter functions or by manipulating their affine transform.

• Size and position are measured from the upper left corner of the page to the upper left corner of the element's unrotated bounding box, and lengths are in points.

• You can set the size, position, and rotation of a page element when it's created or update them afterwards using specific setter functions.

• Scaling and reflection along an edge can be achieved using scaleWidth() and scaleHeight(), including with negative arguments for flipping.

• Lines have their rotation measured by their bounding box rotation, not their visual vertical angle.

There are two different ways you can get and change the size and position of a page element:

1. Using its getter and setter functions for size and position.
2. Manipulating its affine transform, using its getTransform() and setTransform() functions while preserving the inherent size.

Read page element properties

As shown in the figure, size and position are measured with respect to the bounding box of a rendered page element when it has no rotation:

• Left and Top: measured from the upper left corner of the page to the upper left corner of the unrotated bounding box. Use getLeft() and getTop() to read the values.
• Width and Height: the width and height of the unrotated bounding box. Use getWidth() and getHeight() to read the values.
• Rotation: the clockwise rotation with respect to the vertical line around the center of the bounding box. Use getRotation() to read the value.

All lengths are measured in points (pt). The rotation is measured in degrees (°).

Set page element properties

Set the size and position of a page element when you create it using an insert method such as insertShape(). For an existing shape, you can set the size, position, and rotation; you can also set an element's scaling to resize or to reflect it along one of its edges.

At creation

Provide position and size information when creating a page element.

var slide = SlidesApp.getActivePresentation().getSlides()[0];
var shape = slide.insertShape(SlidesApp.ShapeType.TEXT_BOX, 100, 200, 300, 60);
Logger.log('Left: ' + shape.getLeft() + 'pt; Top: '
                    + shape.getTop() + 'pt; Width: '
                    + shape.getWidth() + 'pt; Height: '
                    + shape.getHeight() + 'pt; Rotation: '
                    + shape.getRotation() + ' degrees.');

The preceding script creates a shape on the first slide of the active presentation with the specified position and size and reads the position and size information of the shape. The expected log is:

Left: 100pt; Top: 200pt; Width: 300pt; Height: 60pt; Rotation: 0 degrees.

Size, position, and rotation

Update the size and position of a page element after creation:

• Use setLeft() and setTop() to set the position of the upper left corner of the unrotated bounding box.
• Use setWidth() and setHeight() to set the rendered width and height of the bounding box.
• Use setRotation() to set the clockwise rotation of the bounding box around its center.

The following script creates a shape on the first slide of the active presentation, uses setters to update its position, size, and rotation, and reads the position and size information of the shape.

var slide = SlidesApp.getActivePresentation().getSlides()[0];
var shape = slide.insertShape(SlidesApp.ShapeType.RECTANGLE);
shape.setLeft(100).setTop(200).setWidth(50).setHeight(60).setRotation(90);
Logger.log('Left: ' + shape.getLeft()
                    + 'pt; Top: ' + shape.getTop()
                    + 'pt; Width: ' + shape.getWidth()
                    + 'pt; Height: ' + shape.getHeight()
                    + 'pt; Rotation: ' + shape.getRotation() + '\u00B0.');

The expected log is:

Left: 100pt; Top: 200pt; Width: 50pt; Height: 60pt; Rotation: 90°.

The size, position, and rotation setters can be used in any order or combination. Replacing the third line in the preceding script with the following script produces the same result:

shape.setWidth(55);
shape.setRotation(90).setHeight(60).setLeft(100);
shape.setWidth(50).setTop(200);

Scale a page element

Instead of using setWidth() and setHeight() to set the size of the shape to an absolute value, scaleWidth() and scaleHeight() can be used to stretch or squeeze a page element with a relative scaling factor.

shape.scaleHeight(0.5).scaleWidth(2);

The following figure depicts how the preceding code works on a 45°-rotated square shape. Note that the upper left corner of the bounding box is fixed during scaling.

Reflect a page element

The argument in scaleWidth() and scaleHeight() can be negative so that they can be used to flip a page element horizontally or vertically.

// Flip horizontally along the left edge of the bounding box.
shape.scaleWidth(-1);
// Flip vertically along the top edge of the bounding box.
shape.scaleHeight(-1);

The following figure depicts how the preceding code works on a 45°-rotated shape. Note that the page element is flipped along one of the edges of its bounding box but not its center.

Line rotation

Like other page elements, a line's rotation isn't the vertical angle of the line, but the rotation of its bounding box. When you create a line with specified start and end points, its rotation is always 0°. Dragging the endpoints of the line in Slides UI changes its vertical angle as well as the size and position of its bounding box, but doesn't change its rotation. Using setRotation() rotates the bounding box of the line, which effectively changes its vertical angle. So two lines can have the same visual vertical angle, but different bounding boxes and therefore different size, position, and rotation values.

Limitations

Some sizing and positioning methods are incompatible with some types of page elements. The following table summarizes the methods which are not compatible with certain types of page elements.

All sizing and positioning methods may give unexpected results if the page element has shearing. All limitations are subject to change. Check reference for up-to-date information.

Use affine transforms

For advanced control, the size and position of a page element can also be calculated and adjusted through its inherent (native) size and affine transform.

Google Apps Script provides an interface similar to the Google Slides API for using affine transforms.

• To read properties, you can use an affine transform, which describes how an element is scaled, rotated, sheared, and positioned. To learn how to use an element's transform and inherent (native) size to calculate its visual size on a slide, see Transforms. In Apps Script, use:
  • getInherentWidth() and getInherentHeight() for the inherent (native) size of page elements;
  • getTransform() for the affine transform of the page elements.
• To change properties, you can use affine transforms to perform scaling, rotation, reflection, and more. To learn how to size and position page elements using affine transforms, see Sizing and Positioning. In Apps Script, use:
  • setTransform() to set the affine transform of page elements (similar to ABSOLUTE mode);
  • preconcatenateTransform() to pre-concatenate an affine transform to the current transform of page elements (similar to RELATIVE mode).

The following script creates a shape, sets its transform, reads its inherent size, and reads its affine transform.

var slide = SlidesApp.getActivePresentation().getSlides()[0];
var shape = slide.insertShape(SlidesApp.ShapeType.RECTANGLE);
shape.setTransform(SlidesApp.newAffineTransformBuilder()
                   .setScaleX(2)
                   .setScaleY(1)
                   .setTranslateX(100)
                   .setTranslateY(200)
                   .build());
Logger.log('Inherent width: ' + shape.getInherentWidth()
                              + 'pt; Inherent height: '
                              + shape.getInherentHeight() + 'pt.');

The expected log output is:

Inherent width: 236.2pt; Inherent height: 236.2pt.

The resulting shape has the following transform, rendered size, and position:

AffineTransform{scaleX=2.0, scaleY=1.0, shearX=0.0, shearY=0.0, translateX=100.0, translateY=200.0}
Left: 100pt; Top: 200pt; Width: 472.4pt; Height: 236.2pt; Rotation: 0°.