As the title suggests, this is a button containing an image. More...
Inherits Button.
Public Member Functions | |
| ImageButton (const String &name) | |
| Creates an ImageButton. | |
| ~ImageButton () | |
| Destructor. | |
| void | setImages (bool resizeButtonNowToFitThisImage, bool rescaleImagesWhenButtonSizeChanges, bool preserveImageProportions, const Image &normalImage, float imageOpacityWhenNormal, const Colour &overlayColourWhenNormal, const Image &overImage, float imageOpacityWhenOver, const Colour &overlayColourWhenOver, const Image &downImage, float imageOpacityWhenDown, const Colour &overlayColourWhenDown, float hitTestAlphaThreshold=0.0f) |
| Sets up the images to draw in various states. | |
| Image | getNormalImage () const |
| Returns the currently set 'normal' image. | |
| Image | getOverImage () const |
| Returns the image that's drawn when the mouse is over the button. | |
| Image | getDownImage () const |
| Returns the image that's drawn when the button is held down. | |
Protected Member Functions | |
| bool | hitTest (int x, int y) |
| Tests whether a given point inside the component. | |
| void | paintButton (Graphics &g, bool isMouseOverButton, bool isButtonDown) |
| Subclasses should override this to actually paint the button's contents. | |
As the title suggests, this is a button containing an image.
The colour and transparency of the image can be set to vary when the button state changes.
| ImageButton::ImageButton | ( | const String & | name ) | [explicit] |
Creates an ImageButton.
Use setImage() to specify the image to use. The colours and opacities that are specified here can be changed later using setDrawingOptions().
| name | the name to give the component |
| ImageButton::~ImageButton | ( | ) |
Destructor.
| void ImageButton::setImages | ( | bool | resizeButtonNowToFitThisImage, |
| bool | rescaleImagesWhenButtonSizeChanges, | ||
| bool | preserveImageProportions, | ||
| const Image & | normalImage, | ||
| float | imageOpacityWhenNormal, | ||
| const Colour & | overlayColourWhenNormal, | ||
| const Image & | overImage, | ||
| float | imageOpacityWhenOver, | ||
| const Colour & | overlayColourWhenOver, | ||
| const Image & | downImage, | ||
| float | imageOpacityWhenDown, | ||
| const Colour & | overlayColourWhenDown, | ||
| float | hitTestAlphaThreshold = 0.0f |
||
| ) |
Sets up the images to draw in various states.
| resizeButtonNowToFitThisImage | if true, the button will be immediately resized to the same dimensions as the normal image |
| rescaleImagesWhenButtonSizeChanges | if true, the image will be rescaled to fit the button when the button's size changes |
| preserveImageProportions | if true then any rescaling of the image to fit the button will keep the image's x and y proportions correct - i.e. it won't distort its shape, although this might create gaps around the edges |
| normalImage | the image to use when the button is in its normal state. button no longer needs it. |
| imageOpacityWhenNormal | the opacity to use when drawing the normal image. |
| overlayColourWhenNormal | an overlay colour to use to fill the alpha channel of the normal image - if this colour is transparent, no overlay will be drawn. The overlay will be drawn over the top of the image, so you can basically add a solid or semi-transparent colour to the image to brighten or darken it |
| overImage | the image to use when the mouse is over the button. If you want to use the same image as was set in the normalImage parameter, this value can be a null image. |
| imageOpacityWhenOver | the opacity to use when drawing the image when the mouse is over the button |
| overlayColourWhenOver | an overlay colour to use to fill the alpha channel of the image when the mouse is over - if this colour is transparent, no overlay will be drawn |
| downImage | an image to use when the button is pressed down. If set to a null image, the 'over' image will be drawn instead (or the normal image if there isn't an 'over' image either). |
| imageOpacityWhenDown | the opacity to use when drawing the image when the button is pressed |
| overlayColourWhenDown | an overlay colour to use to fill the alpha channel of the image when the button is pressed down - if this colour is transparent, no overlay will be drawn |
| hitTestAlphaThreshold | if set to zero, the mouse is considered to be over the button whenever it's inside the button's bounding rectangle. If set to values higher than 0, the mouse will only be considered to be over the image when the value of the image's alpha channel at that position is greater than this level. |
| Image ImageButton::getNormalImage | ( | ) | const |
Returns the currently set 'normal' image.
| Image ImageButton::getOverImage | ( | ) | const |
Returns the image that's drawn when the mouse is over the button.
If a valid 'over' image has been set, this will return it; otherwise it'll just return the normal image.
| Image ImageButton::getDownImage | ( | ) | const |
Returns the image that's drawn when the button is held down.
If a valid 'down' image has been set, this will return it; otherwise it'll return the 'over' image or normal image, depending on what's available.
| bool ImageButton::hitTest | ( | int | x, |
| int | y | ||
| ) | [protected, virtual] |
Tests whether a given point inside the component.
Overriding this method allows you to create components which only intercept mouse-clicks within a user-defined area.
This is called to find out whether a particular x, y coordinate is considered to be inside the component or not, and is used by methods such as contains() and getComponentAt() to work out which component the mouse is clicked on.
Components with custom shapes will probably want to override it to perform some more complex hit-testing.
The default implementation of this method returns either true or false, depending on the value that was set by calling setInterceptsMouseClicks() (true is the default return value).
Note that the hit-test region is not related to the opacity with which areas of a component are painted.
Applications should never call hitTest() directly - instead use the contains() method, because this will also test for occlusion by the component's parent.
Note that for components on the desktop, this method will be ignored, because it's not always possible to implement this behaviour on all platforms.
| x | the x coordinate to test, relative to the left hand edge of this component. This value is guaranteed to be greater than or equal to zero, and less than the component's width |
| y | the y coordinate to test, relative to the top edge of this component. This value is guaranteed to be greater than or equal to zero, and less than the component's height |
Reimplemented from Component.
| void ImageButton::paintButton | ( | Graphics & | g, |
| bool | isMouseOverButton, | ||
| bool | isButtonDown | ||
| ) | [protected, virtual] |
Subclasses should override this to actually paint the button's contents.
It's better to use this than the paint method, because it gives you information about the over/down state of the button.
| g | the graphics context to use |
| isMouseOverButton | true if the button is either in the 'over' or 'down' state |
| isButtonDown | true if the button should be drawn in the 'down' position |
Implements Button.
