How to use the Check component
The Check class may be selected and deselected when clicked or tapped — similar to a toggle button. A check displays text and an icon that indicates the current selection — along with a variety of layout options. Checks have separate states for each of the different pointer phases — with additional variations when selected. The icon and font styles may be customized for each state.
The Basics
Start by creating a Check control, give it some text to display, and add it to the the display list.
var check = new Check();
check.text = "Click Me";
this.addChild(check);
A check may be selected and deselected when it is triggered, or it can be changed programmatically by setting the selected property.
check.selected = true;
Add an event listener for Event.CHANGE to perform an action when the user changes the check's selection.
check.addEventListener(Event.CHANGE, check_changeHandler);
Check for the new value of the selected property in the listener function.
function check_changeHandler(event:Event):Void {
var check = cast(event.currentTarget, Check);
trace("check.selected change: " + check.selected);
}
States
When the user interacts with a check using the mouse, keyboard, or touchscreen, its state will change, which may affect its appearance. For instance, the check's icon and font styles may all be rendered differently in different states.
Similar to ToggleButton, the Check component uses the ToggleButtonState enum, which provides the following values.
UP(selected:Bool)is the check's default state when the user is not interacting with it, and the check is enabled.DOWN(selected:Bool)is the state when the user presses the check with a mouse, touchscreen, or by pressingKeyboard.SPACEwhen the check is focused.HOVER(selected:Bool)is the state when the mouse is hovering over the check. This state is not used for touchscreens or keyboard interaction.DISABLED(selected:Bool)is the check's state when itsenabledproperty has been set tofalse.
Notice that each state also defines a boolean value to indicate if the check is selected or not. DOWN(true) and DOWN(false) both indicate that the check is currently pressed down, but the value of true indicates that it is currently selected, while false means that it is not selected.
Styles
A number of styles may be customized on a Check component, including the icon and font styles. Several more styles may be used to adjust the layout of the check's children.
Font styles
The font styles of the check's text may be customized by passing an openfl.text.TextFormat object to the textFormat property.
check.textFormat = new TextFormat("Helvetica", 20, 0x3c3c3c);
If the check's text should use different font styles when the check is selected, pass a TextFormat to the selectedTextFormat property.
check.selectedTextFormat = new TextFormat("Helvetica", 20, 0x9a9a9a, true);
Finally, the check's text may use different font styles in a more fine-grained matter — by targeting an exact state. Use the setTextFormatForState() method to pass in a state value and a TextFormat.
check.setTextFormatForState(DISABLED(false), new TextFormat("Helvetica", 20, 0xcc0000));
Using the code above, the color of the check's text will change when the check is disabled and not selected.
When font styles aren't available for a specific state, the check will use the default textFormat as a fallback (preferring selectedTextFormat when selected, of course).
Icon skin
Give the check an icon using the icon property. The following example sets it to an OpenFL Shape instance.
var icon = new Shape();
icon.lineStyle(1.0, 0x999999);
icon.beginFill(0xcccccc);
icon.graphics.drawRect(0.0, 0.0, 32.0, 32.0);
icon.graphics.endFill();
check.icon = icon;
The appearance of the check's icon may change when the check is selected. In the next example, the another OpenFL Shape is passed to the check's selectedIcon property.
var selectedIcon = new Shape();
selectedIcon.lineStyle(1.0, 0x999999);
selectedIcon.beginFill(0xcccccc);
selectedIcon.graphics.drawRect(0.0, 0.0, 32.0, 32.0);
selectedIcon.graphics.endFill();
selectedIcon.lineStyle(0.0);
selectedIcon.beginFill(0xccccff);
selectedIcon.graphics.drawRect(4.0, 4.0, 24.0, 24.0);
selectedIcon.graphics.endFill();
check.selectedIcon = selectedIcon;
The icon may be customized for an exact state too. In the next example, the setIconForState() method is called to pass in a custom icon for the DOWN(false) state.
var downIcon = new Shape();
downIcon.lineStyle(1.0, 0x999999);
downIcon.beginFill(0xccccdd);
downIcon.graphics.drawRect(0.0, 0.0, 32.0, 32.0);
downIcon.graphics.endFill();
check.setIconForState(DOWN(false), downIcon);
Layout
Padding may be added on each side of the check, including top, right, bottom, and left.
check.paddingTop = 5.0;
check.paddingRight = 8.0;
check.paddingBottom = 5.0;
check.paddingLeft = 8.0;
The icon may be positioned on any side of the check's text. For instance, the following example moves the icon above the text, so that the icon and text are stacked vertically.
check.iconPosition = TOP;
Set the iconPosition property to any of the RelativePosition values.
The gap refers to the space, measured in pixels, between the icon and the text.
check.gap = 10.0;
The horizontalAlign and verticalAlign properties will adjust the alignment of the icon and text inside the check, allowing you to anchor them at the edges or in the center.
check.horizontalAlign = CENTER;
check.verticalAlign = MIDDLE;