Class: MiniGL::Button

Inherits:
Component show all
Defined in:
lib/minigl/forms.rb

Overview

This class represents a button.

Direct Known Subclasses

ToggleButton

Instance Attribute Summary collapse

Attributes inherited from Component

#enabled, #h, #params, #visible, #w, #x, #y

Instance Method Summary collapse

Constructor Details

#initialize(x, y, font, text, img, text_color = 0, disabled_text_color = 0, over_text_color = 0, down_text_color = 0, center_x = true, center_y = true, margin_x = 0, margin_y = 0, width = nil, height = nil, params = nil, &action) ⇒ Button

Creates a button.

Parameters:

x

The x-coordinate where the button will be drawn in the screen.

y

The y-coordinate where the button will be drawn in the screen.

font

The Gosu::Font object that will be used to draw the button text.

text

The button text. Can be nil or empty.

img

A spritesheet containing four images in a column, representing, from top to bottom, the default state, the hover state (when the mouse is over the button), the pressed state (when the mouse button is down and the cursor is over the button) and the disabled state. If nil, the width and height parameters must be provided.

text_color

Color of the button text, in hexadecimal RRGGBB format.

disabled_text_color

Color of the button text, when it’s disabled, in hexadecimal RRGGBB format.

over_text_color

Color of the button text, when the cursor is over it (hexadecimal RRGGBB).

down_text_color

Color of the button text, when it is pressed (hexadecimal RRGGBB).

center_x

Whether the button text should be horizontally centered in its area (the area is defined by the image size, if an image is given, or by the width and height parameters, otherwise).

center_y

Whether the button text should be vertically centered in its area (the area is defined by the image size, if an image is given, or by the width and height parameters, otherwise).

margin_x

The x offset, from the button x-coordinate, to draw the text. This parameter is used only if center is false.

margin_y

The y offset, from the button y-coordinate, to draw the text. This parameter is used only if center is false.

width

Width of the button clickable area. This parameter is used only if img is nil.

height

Height of the button clickable area. This parameter is used only if img is nil.

params

An object containing any parameters you want passed to the action block. When the button is clicked, the following is called:

@action.call @params

Note that this doesn’t force you to declare a block that takes parameters.

action

The block of code executed when the button is clicked (or by calling the click method).



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# File 'lib/minigl/forms.rb', line 96

def initialize(x, y, font, text, img, text_color = 0, disabled_text_color = 0, over_text_color = 0, down_text_color = 0,
               center_x = true, center_y = true, margin_x = 0, margin_y = 0, width = nil, height = nil, params = nil, &action)
  super x, y, font, text, text_color, disabled_text_color
  @over_text_color = over_text_color
  @down_text_color = down_text_color
  @img =
    if img; Res.imgs img, 1, 4, true
    else; nil; end
  @w =
    if img; @img[0].width
    else; width; end
  @h =
    if img; @img[0].height
    else; height; end
  if center_x; @text_x = x + @w / 2 if @w
  else; @text_x = x + margin_x; end
  if center_y; @text_y = y + @h / 2 if @h
  else; @text_y = y + margin_y; end
  @center_x = center_x
  @center_y = center_y
  @action = action
  @params = params

  @state = :up
  @img_index = @enabled ? 0 : 3
end

Instance Attribute Details

#state ⇒ Object (readonly)

The current state of the button.



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# File 'lib/minigl/forms.rb', line 48

def state
  @state
end

#text ⇒ Object

The text of the button.



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# File 'lib/minigl/forms.rb', line 51

def text
  @text
end

Instance Method Details

#click ⇒ Object

Executes the button click action.



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# File 'lib/minigl/forms.rb', line 174

def click
  @action.call @params
end

#draw(alpha = 0xff, z_index = 0) ⇒ Object

Draws the button in the screen.

Parameters:

alpha

The opacity with which the button will be drawn. Allowed values vary between 0 (fully transparent) and 255 (fully opaque).

z_index

The z-order to draw the object. Objects with larger z-orders will be drawn on top of the ones with smaller z-orders.



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# File 'lib/minigl/forms.rb', line 198

def draw(alpha = 0xff, z_index = 0)
  return unless @visible

  color = (alpha << 24) | 0xffffff
  text_color =
    if @enabled
      if @state == :down
        @down_text_color
      else
        @state == :over ? @over_text_color : @text_color
      end
    else
      @disabled_text_color
    end
  text_color = (alpha << 24) | text_color
  @img[@img_index].draw @x, @y, z_index, 1, 1, color if @img
  if @text
    if @center_x or @center_y
      rel_x = @center_x ? 0.5 : 0
      rel_y = @center_y ? 0.5 : 0
      @font.draw_rel @text, @text_x, @text_y, z_index, rel_x, rel_y, 1, 1, text_color
    else
      @font.draw @text, @text_x, @text_y, z_index, 1, 1, text_color
    end
  end
end

#enabled=(value) ⇒ Object

:nodoc:



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# File 'lib/minigl/forms.rb', line 225

def enabled=(value) # :nodoc:
  @enabled = value
  @state = :up
  @img_index = 3
end

#set_position(x, y) ⇒ Object

Sets the position of the button in the screen.

Parameters:

x

The new x-coordinate for the button.

y

The new y-coordinate for the button.



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# File 'lib/minigl/forms.rb', line 183

def set_position(x, y)
  if @center_x; @text_x = x + @w / 2
  else; @text_x += x - @x; end
  if @center_y; @text_y = y + @h / 2
  else; @text_y += y - @y; end
  @x = x; @y = y
end

#update ⇒ Object

Updates the button, checking the mouse movement and buttons to define the button state.



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# File 'lib/minigl/forms.rb', line 125

def update
  return unless @enabled and @visible

  mouse_over = Mouse.over? @x, @y, @w, @h
  mouse_press = Mouse.button_pressed? :left
  mouse_rel = Mouse.button_released? :left

  if @state == :up
    if mouse_over
      @img_index = 1
      @state = :over
    else
      @img_index = 0
    end
  elsif @state == :over
    if not mouse_over
      @img_index = 0
      @state = :up
    elsif mouse_press
      @img_index = 2
      @state = :down
    else
      @img_index = 1
    end
  elsif @state == :down
    if not mouse_over
      @img_index = 0
      @state = :down_out
    elsif mouse_rel
      @img_index = 1
      @state = :over
      click
    else
      @img_index = 2
    end
  else # :down_out
    if mouse_over
      @img_index = 2
      @state = :down
    elsif mouse_rel
      @img_index = 0
      @state = :up
    else
      @img_index = 0
    end
  end
end