The mouse capplet in the GNOME Control Center helps to configure properties of the mouse. These are: for the General tab: mouse acceleration, mouse sensitivity, double-click timout, drag and drop treshold, pointer location and left handed or right handed mouse usage for the Accessibility tab: simulated secondary click and dwell click The General tab offers the commonly used settings of the mouse. A user controls the mouse differently based on him being right or left handed. If he is right handed, the mouse typically sits on the right hand side of the desk. The primary button (action button) is on the left of the mouse, so that he can press it with his index finger, while the secondary button (menu button) is on the right. However, if he is left handed, the mouse sits on the left hand side of the desk. Consequently, in order to allow him to operate the primary button with his index finger of his left hand, the primary and the secondary button of the mouse have to be swapped. That is the purpose of the Mouse Orientation setting: select the Right-handed button if you are right handed, or the Left-handed button if you are left handed. When using the setting appropriate to him, the user has the primary button under his index finger. Sometimes, the user loses where the pointer is. If he selects the Show position of pointer when the Control key is pressed, he can make the pointer reappear by pressing the control key. Every user has different favorites regarding the relation between the movement of the mouse and the movement of the pointer. In order to tune it to his taste, he can use the Acceleration and the Sensitivity settings: Acceleration: it sets the linear factor between mouse movement and pointer movement Sensitivity: it sets the threshold speed at which the mouse will start accelerating For example, by setting the sensitivity to its lowest, the mouse will move all the time with no acceleration adjustment; in this case, there is a perfect mouse distance to pixel distance ratio. Drag and drop is clicking an object, and dragging it to another place on the screen, causing an event to occur. You need to drag it a certain amount of distance before the system will recognize it as a drag and drop operation. To configure how far to drag it, move the Treshold slider left or right. When a user performs two clicks with the primary button, the system considers them as a double-click or as two single clicks depending on the delay that has elapsed between the two clicks. With the Timeout slider, the user can set the maximum delay that can elapse between the two clicks for them to be still considered as a double-click. If the delay between the two clicks is greater than the maximum delay that has been set, the two clicks are considered as two single clicks instead of a double click. Consequently: the shorter the timeout, the less time can elapse between the two clicks of a double-click. The user can test the timeout that he has set by clicking on the light bulb, that will light on, if a double-click is detected. The Accessibility tab brings additional functions to the mouse. It allows the the user to perform a secondary click by using the primary button; it also allows him to perform all the different click types without using any hardware button. There are users that can use only one mouse button. By activating the Simulated Secondary Click, these users have a direct way to perform secondary clicks with their unique mouse button. In fact, the secondary click occurs automatically when the user keeps the primary button pressed for a determined delay without moving the mouse. The Simulated Secondary Click also offers a slider named Delay to configure how long the user has to press the button and keep the mouse motionless, before the secondary click is automatically performed. There are users that cannot use any hardware button. By activating the Dwell Click, they can have the mouse perform the various clicks without pressing any mousebutton. The click types that can be performed are: single click, double-click, drag click and secondary click. To make the mouse perform the clicks without a mousebutton being pressed, the user has to put a mark in the box named Initiate click when stopping pointer movement. How the click is completed and how the click type is chosen depends on what dwell mode the user is using. The two available modes are: automatic click completion with click type chosen beforehand click completion and click type choice by a mouse gesture after click initiation With the Delay slider, the user can configure how long the pointer has to be motionless for the click to be initiated. For people that have trouble to keep the mouse motionless, there is the Motion Treshold slider. When the slider is set towards low, even little mouse movements are considered; however, by setting a higher treshold, the mouse has to traverse a bigger distance before it is considered as moving. As said above, the user can choose between two modes for the click type choice and click completion: This mode is active when the user selects Choose type of click beforehand. In fact, after the mouse has been motionless for the above predefined delay, the system will automatically perform the click type that is selected in the Click Type Window. After the click has occurred, the single click type will be automatically restored. In order to choose another click type, the user has to perform an automatic click on the button in the Click Type Window that corresponds to its click type choice. To make the Click Type Window appear on the screen, the user has to put a mark into the checkbox named Show click type window. Some users might prefer to use the Dwell Click panel applet instead of the Click Type Window. The advantage of the panel applet is that it does not cover any open window on the desktop. This mode is used when the user selects Choose type of click with mouse gestures. In fact, after the mouse has been motionless for the above predefined delay, the shape of the pointer will change for a little while: If the user moves the mouse while it is showing the alternative shape, a click is performed and the pointer returns to its normal shape. The type of click performed depends on the direction of the movement of the mouse. If the mouse stays motionless until the pointer returns to its normal shape, the user can move the mouse without a click being performed. The next dwell click can be performed when the mouse stops moving again. The user also has the possibility to match click type with movement direction by using the 4 popups available under this mode.