# The Canvas

## Canvas Introduction

The canvas is the main part of Dia. The Dia canvas is the window where all the user's objects will be placed on the screen and arranged. When the diagram is printed or saved, the contents of the canvas will be saved.

## Grid Lines

Grid lines are similar to the lines on graph paper. They allow the user to easily align objects on the canvas. The grid lines can be temporarily hidden for the current document choosing the menus item View Show Grid . The grid lines can be turned hidden for all new documents by going into File Preferences . In the Grid Lines tab, click the checkbox labelled Visible and leave it empty to hide the grid lines.

## Rulers

Rulers appear on the top and the left of the Dia canvas. They show, in centimeters, how large your canvas is.

On each ruler exists an arrow. The arrow moves on the ruler in coordination with where the mouse pointer is. For example, if the user moves the mouse up, the vertical ruler's arrow will move up, indicating the change. These arrows become useful when an object needs to line up exactly at a certain measurement point.

Rulers can be temporarily hidden for the current document by choosing the menu item View Show Rulers . Rulers, unlike grid lines, cannot be turned off by default for new documents.

## Background Colour

The background colour option allows you to change what the background looks like in the canvas. By default, the colour is white. However, the colour can be changed by going into View Diagram Properties Background and clicking on the bar. The bar displays the current background colour. The gridlines will change their color automatically to stay visible if the background color is changed to black.

## Zooming

Zooming allows the user to get up closer to their diagram. This helps to let the user make precision drawings.

The canvas can be zoomed up to 400%. Zoom can be done by clicking on the magnifying glass on the toolbox and clicking on the canvas. To zoom out, hold the shift button and click again on the canvas.