Control - Check Box

$images\btn_ctrl_checkbox.gif$ Insert a check box into the form.

To Add a Check Box to a Form

1. Click on the Insert Check Box button in the Tools toolbar.

2. Click and drag the location and size where it is to be created in the form.

3. Continue to create any additional check boxes desired.

4. Right click onto each check box and choose Properties from the context menu.

5. Set the properties for the check box as desired.

6. Move, resize and align the check box as desired.

Properties normally both return and set that particular property. The easiest way to edit properties is through the context menu's properties dialog for that control.

Some attributes of controls, such as their size or position are properties not of the control but of the container for the control, in this case the Form itself. To change the size or position of controls we can simply click on them and resize or drag them to a new position.

Keep in mind that programs can change the properties of controls at run time. Although this documentation is written as though the properties are set at design time using the Properties dialog for this control, there are many situations in which program code will be used to change a control's properties at run time.

Note: All properties and controls are prefaced with "wl" to indicate they are the windowless lightweight versions of the controls and properties settings. The "wl" prefix is suppressed in the documentation below to enhance legibility.

Properties

In addition to the properties listed below, a Control tab provides access to certain frequently used form properties for this control. See the Form Properties topic for information on those properties.

	Check Box
General
Caption	Text used to label the check box. Font is set in the font tab.
MousePointer	The type of mouse pointer displayed when over the check box. Choose from 16 different types plus a custom pointer
Appearance	3D or Flat. 3D is the standard Windows look.
Alignment	Places check box to left or right of caption within the size of the control.
OLEDropMode	Set to None (default) if the check box does not accept OLE drops and is to display the No Drop cursor if an OLE drop is attempted. Set to Manual, the check box will trigger OLE drop events, allowing programs to handle the OLE drop operation in code.
Style	Standard (default) or Graphical. In Standard style check boxes display as a box/button with the caption label next to it. In graphical style, check boxes display as a button that can be pushed in/out and may also display an associated graphic.
Value	Default state of the control: Unchecked, Checked and Grayed (dimmed).
Enabled	True or False. True means the object can respond to user-generated events, false prevents it from responding. We can disable a control like a text box if we wish it to simply display information in a read-only way.
UseMaskColor	If checked, enables use of mask color in a button's picture if the Style is set to graphical. A mask color is the color that is to be made transparent.

Color
Back Color	Color to be used for the check box's background, normally seen only when Flat Style is used.
Fore Color	Color to be used for the check box's foreground, the color of the text caption.
Mask Color	Color to be treated as transparent in an image used with the button when UseMaskColor is checked and Style is set to graphical.
Color Set	Choose from Standard Colors (standard Windows non-dithered colors) or Windows System Colors. The latter will be defined by the user's Control Panel settings and is normally the setting used so that the form changes appearance like the rest of Windows if the Control Panel settings are changed.
Color Palette	Displays available colors. Click on the property to be changed to highlight it in the Properties pane, click on the desired color in the Color Palette pane and then press Apply.
Edit Custom Color	Change the custom color presented in the Color Palette when the Color Set is set to Windows System Colors.

Font
Properties	Font properties that may be changes.
Font	Choose a font installed on this system. It's wise to choose standard Windows fonts such as MS Sans Serif that are universally available.
Size	Size of font, in points.
Effects	Bold, Italic, Underline or Strikeout.
Sample Text	A preview of the selected settings.

Picture
DisabledPicture	Graphic to show when control is disabled if Style is set to graphical.
DownPicture	Graphic to show on an enabled control in the DOWN position if Style is set to graphical.
MouseIcon	Custom icon to use when the MousePointer property is set to 99. Like Visual Basic, will not load animated cursor (.ani) files.
Picture	Graphic to show on an enabled control in the UP position if Style is set to graphical.

	Note: graphics are loaded at design time and saved within the project. When browsing to find the graphic to be used, .bmp, .ico, .wmf, .gif or .jpeg files may be used.

Examples

$images\ctrl_checkbox_3d.gif$ $images\ctrl_checkbox_flat.gif$

Appearance property set to 3D (left) and flat (right).

Check boxes are often used as "mode" buttons in graphical style. Suppose we want our form to control the display of a map that shows airports, bus stations and train stations. Using Manifold's image capabilities, we have created six small images, each of which is 30 x 30 pixels in size:

$images\airport.gif$ $images\airport_bw.gif$ $images\bus_station.gif$ $images\bus_station_bw.gif$ $images\train_station.gif$ $images\train_station_bw.gif$

The gray versions are simply copies of the green versions that were desaturated and had the lightness increased using Manifold's Hue / Saturation command. We first create three check boxes and clear their caption property:

$images\ctrl_checkbox_eg01.gif$

In the default standard style they are just ordinary check boxes. We have created these check boxes with a Height and a Width of 40 pixels each.

$images\ctrl_checkbox_eg01a.gif$

If we choose graphical style for each of the check boxes, they appear as a 3D button.

$images\ctrl_checkbox_eg02.gif$

We can also choose the Picture property for each of them to use the gray picture in their "up" position.

$images\dlg_ctrl_picture_airport.gif$

For the DownPicture property we use the green picture.

$images\ctrl_checkbox_eg03.gif$

When the form is run, pressing the button (equivalent to checking the check box) switches the green picture into the button. This is a nice way of emphasizing that this button is pushed in. In the illustration above we have chosen airports and bus stations.

$images\ctrl_checkbox_eg04.gif$

Here, we have chosen just train stations.

Note: It's very cool we can use graphics so easily in Manifold forms. However, one should use them with restraint to avoid cluttering up forms with distracting graphical junk. Sometimes a plain check box is a better approach.