Refactor label into own scalable component

Author	DaveJarvis <email>
Date	2020-07-19 16:16:55 GMT-0700
Commit	b931a58b5fe5646520a53768f3ec2f98bf4301da
Parent	a8294b1

src/main/com/whitemagicsoftware/kmcaster/EventHandler.java

		package com.whitemagicsoftware.kmcaster;

		-import javax.swing.*;
		+import com.whitemagicsoftware.kmcaster.ui.AutofitLabel;
		+
		import java.awt.*;
		-import java.awt.font.TextLayout;
		import java.beans.PropertyChangeEvent;
		import java.beans.PropertyChangeListener;

		final var switchValue = e.getNewValue().toString();

		- // True or false indicates a non-regular key was pressed.
		+ // True indicates a modifier key was pressed; false indicates a key was
		+ // released (doesn't matter what kind of key).
		final var context =
		(!"false".equals( switchValue ) && !"true".equals( switchValue ))


		if( !"false".equals( value ) ) {
		- final var bounds = component.getBounds();
		- final var insets = component.getInsets();
		-
		- bounds.x += insets.left;
		- bounds.y += insets.top;
		- bounds.width -= insets.right + insets.left;
		- bounds.height -= insets.bottom + insets.top;
		-
		- final var label = createLabel( value, bounds, component.getGraphics() );
		-
		- label.setLocation( insets.left, insets.top );
		+ final var label = new AutofitLabel( value, LABEL_FONT, LABEL_COLOUR );

		component.add( label );
		- component.repaint();
		- }
		- }
		- }
		-
		- /**
		- * Creates a label that can fit within bounds defined by the given
		- * {@link Rectangle} using the given {@link Graphics} context for deriving
		- * the actualized font dimensions (for a particular font point size).
		- *
		- * @param text The label's text.
		- * @param r The label's maximum width and height.
		- * @param graphics The graphics context used to determine font scale (must
		- * be a {@link Graphics2D instance}).
		- * @return A label adjusted to the given dimensions.
		- */
		- private JLabel createLabel(
		- final String text, final Rectangle r, final Graphics graphics ) {
		- assert text != null;
		- assert r != null;
		- assert graphics != null;
		-
		- final int width = (int) r.getWidth();
		- final int height = (int) r.getHeight();
		-
		- final var label = new JLabel( text );
		- label.setFont( LABEL_FONT );
		- label.setSize( width, height );
		- label.setForeground( LABEL_COLOUR );
		-
		- final var scaledFont = scaleFont( label, r, graphics );
		- label.setFont( scaledFont );
		-
		- return label;
		- }
		-
		- /**
		- * Adjusts the given {@link Font}/{@link String} size such that it fits
		- * within the bounds of the given {@link Rectangle}.
		- *
		- * @param label Contains the text and font to scale.
		- * @param dst The bounds for fitting the string.
		- * @param graphics The context for rendering the string.
		- * @return A new {@link Font} instance that is guaranteed to write the given
		- * string within the bounds of the given {@link Rectangle}.
		- */
		- public Font scaleFont(
		- final JLabel label, final Rectangle dst, final Graphics graphics ) {
		- assert label != null;
		- assert dst != null;
		- assert graphics != null;
		- final var frc = ((Graphics2D) graphics).getFontRenderContext();
		-
		- final var dstWidthPx = dst.getWidth();
		- final var dstHeightPx = dst.getHeight();
		-
		- final var text = label.getText();
		-
		- var minSizePt = 1f;
		- var maxSizePt = 1000f;
		- var scaledFont = label.getFont();
		- float scaledPt = scaledFont.getSize();
		-
		- while( maxSizePt - minSizePt > 1f ) {
		- scaledFont = scaledFont.deriveFont( scaledPt );
		-
		- final var layout = new TextLayout( text, scaledFont, frc );
		- final var fontWidthPx = layout.getVisibleAdvance();
		- final var metrics = scaledFont.getLineMetrics( text, frc );
		- final var fontHeightPx = metrics.getHeight();
		-
		- if( (fontWidthPx > dstWidthPx) \|\| (fontHeightPx > dstHeightPx) ) {
		- maxSizePt = scaledPt;
		- }
		- else {
		- minSizePt = scaledPt;
		}
		-
		- scaledPt = (minSizePt + maxSizePt) / 2;
		}
		-
		- // Round down to guarantee fit.
		- return scaledFont.deriveFont( (float) Math.floor( scaledPt ) );
		}
		}

src/main/com/whitemagicsoftware/kmcaster/HardwareImages.java

		*/
		public class HardwareImages {
		-
		private final static String DIR_IMAGES = "/images";
		private final static String DIR_IMAGES_KEYBOARD = DIR_IMAGES + "/key";
		private final static String DIR_IMAGES_MOUSE = DIR_IMAGES + "/mouse";

		private final static SvgRasterizer sRasterizer = new SvgRasterizer();

		private final Map<HardwareSwitch, HardwareComponent<HardwareState, Image>>
		mSwitches = new HashMap<>();
		- private final Dimension mDimension;
		+
		+ /**
		+ * Images are scaled to these dimensions, maintaining aspect ratio. The
		+ * height constrains the width, so as long as the width is sufficiently
		+ * large, the application's window will adjust to fit.
		+ */
		+ private final Dimension mDimension = new Dimension( 1024, 60 );

		/**
		* Constructs an enumerated type that represents the different types of
		* images shown when keyboard and mouse events are triggered.
		- *
		- * @param dimension The image will be scaled to the given dimensions, aspect
		- * ratio is maintained.
		*/
		- public HardwareImages( final Dimension dimension ) {
		- assert dimension != null;
		-
		- mDimension = dimension;
		-
		+ public HardwareImages() {
		final var mouseReleased = mouseImage( "0" );
		final var mouseStates = new HardwareComponent<HardwareState, Image>();


		private Image createImage( final String path ) {
		- assert mDimension != null;
		-
		final var resource = format( "%s.svg", path );

src/main/com/whitemagicsoftware/kmcaster/KmCaster.java

		@SuppressWarnings("unused")
		public class KmCaster extends JFrame {
		- private static final Dimension FRAME_DIMENSIONS = new Dimension( 484, 70 );
		- private static final Dimension HARDWARE_DIMENSIONS = new Dimension(
		- (int) FRAME_DIMENSIONS.getWidth(),
		- (int) (FRAME_DIMENSIONS.getHeight() - 10) );
		private static final Color TRANSPARENT = new Color( 0, 0, 0, 0 );
		private static final Color TRANSLUCENT = new Color( .2f, .2f, .2f, 0.5f );

		private final static float TYPING_SPEED_CPMS = TYPING_SPEED_CPS / 1000;

		- private final HardwareImages mHardwareImages =
		- new HardwareImages( HARDWARE_DIMENSIONS );
		+ private final HardwareImages mHardwareImages = new HardwareImages();
		private final EventHandler mEventHandler =
		new EventHandler( mHardwareImages );

		setAlwaysOnTop( true );
		setBackground( TRANSPARENT );
		- setSize( FRAME_DIMENSIONS );
		setShape( createShape() );
		}

src/main/com/whitemagicsoftware/kmcaster/ui/AutofitLabel.java

		+/*
		+ * Copyright 2020 White Magic Software, Ltd.
		+ *
		+ * All rights reserved.
		+ *
		+ * Redistribution and use in source and binary forms, with or without
		+ * modification, are permitted provided that the following conditions are met:
		+ *
		+ * o Redistributions of source code must retain the above copyright
		+ * notice, this list of conditions and the following disclaimer.
		+ *
		+ * o Redistributions in binary form must reproduce the above copyright
		+ * notice, this list of conditions and the following disclaimer in the
		+ * documentation and/or other materials provided with the distribution.
		+ *
		+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
		+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
		+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
		+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
		+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
		+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
		+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
		+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		+ */
		+package com.whitemagicsoftware.kmcaster.ui;
		+
		+import javax.swing.*;
		+import java.awt.*;
		+import java.awt.font.FontRenderContext;
		+import java.awt.font.TextLayout;
		+
		+import static java.awt.event.HierarchyEvent.PARENT_CHANGED;
		+
		+/**
		+ * Responsible for changing the {@link JLabel}'s font size
		+ */
		+public class AutofitLabel extends JLabel {
		+
		+ /**
		+ * Constructs an instance of {@link AutofitLabel} that will rescale itself
		+ * to the parent {@link Container}, automatically.
		+ *
		+ * @param text The text to write on the container's graphics context.
		+ * @param font The font to use when writing the text.
		+ * @param color The colour to use when writing hte text.
		+ */
		+ public AutofitLabel( final String text, final Font font, final Color color ) {
		+ super( text );
		+ setFont( font );
		+ setForeground( color );
		+
		+ addHierarchyListener( e -> {
		+ if( (e.getChangeFlags() & PARENT_CHANGED) != 0 ) {
		+ if( getParent() == e.getChangedParent() ) {
		+ rescale();
		+ }
		+ }
		+ } );
		+ }
		+
		+ /**
		+ * Rescales the constructed font to fit within the bounds of the parent
		+ * {@link Container}. This must only be called after the parent
		+ * {@link Container} has been set, otherwise there will be no
		+ * {@link Graphics} context available to compute the maximum {@link Font}
		+ * size that will fit the parent's {@link Rectangle} bounds.
		+ */
		+ private void rescale() {
		+ final var component = getParent();
		+ final var bounds = component.getBounds();
		+ final var insets = component.getInsets();
		+
		+ bounds.x += insets.left;
		+ bounds.y += insets.top;
		+ bounds.width -= insets.left + insets.right;
		+ bounds.height -= insets.top + insets.bottom;
		+
		+ setLocation( insets.left, insets.top );
		+ setSize( bounds.width, bounds.height );
		+ setFont( computeScaledFont() );
		+ }
		+
		+ /**
		+ * Calculates a new {@link Font} size such that it fits within the bounds
		+ * of this label instance. This uses the label's current size, which must
		+ * be set prior to calling this method.
		+ *
		+ * @return A new {@link Font} instance that is guaranteed to write the given
		+ * string within the bounds of the given {@link Rectangle}.
		+ */
		+ private Font computeScaledFont() {
		+ final var frc = getFontRenderContext();
		+ final var text = getText();
		+
		+ final var dstWidthPx = getWidth();
		+ final var dstHeightPx = getHeight();
		+
		+ var minSizePt = 1f;
		+ var maxSizePt = 200f;
		+ var scaledFont = getFont();
		+ float scaledPt = scaledFont.getSize();
		+
		+ while( maxSizePt - minSizePt > 1f ) {
		+ scaledFont = scaledFont.deriveFont( scaledPt );
		+
		+ final var layout = new TextLayout( text, scaledFont, frc );
		+ final var fontWidthPx = layout.getVisibleAdvance();
		+ final var metrics = scaledFont.getLineMetrics( text, frc );
		+ final var fontHeightPx = metrics.getHeight();
		+
		+ if( (fontWidthPx > dstWidthPx) \|\| (fontHeightPx > dstHeightPx) ) {
		+ maxSizePt = scaledPt;
		+ }
		+ else {
		+ minSizePt = scaledPt;
		+ }
		+
		+ scaledPt = (minSizePt + maxSizePt) / 2;
		+ }
		+
		+ // Round down to guarantee fit.
		+ return scaledFont.deriveFont( (float) Math.floor( scaledPt ) );
		+ }
		+
		+ /**
		+ * Gets the {@link FontRenderContext} for the parent {@link Container}'s
		+ * {@link Graphics} context, casting it to a {@link Graphics2D} context.
		+ *
		+ * @return The parent's {@link Graphics2D} context.
		+ */
		+ private FontRenderContext getFontRenderContext() {
		+ return ((Graphics2D) getGraphics()).getFontRenderContext();
		+ }
		+}

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