Add modern implementation of the Slider widget and deprecate the old …

…one (MinecraftForge#8496)

src/main/java/net/minecraftforge/client/gui/widget/ForgeSlider.java

@@ -0,0 +1,220 @@
+/*
+ * Minecraft Forge - Forge Development LLC
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.client.gui.widget;
+
+import net.minecraft.client.gui.components.AbstractSliderButton;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.TextComponent;
+import net.minecraft.util.Mth;
+import org.lwjgl.glfw.GLFW;
+
+import java.text.DecimalFormat;
+
+/**
+ * Slider widget implementation which allows inputting values in a certain range with optional step size.
+ */
+public class ForgeSlider extends AbstractSliderButton
+{
+    protected Component prefix;
+    protected Component suffix;
+
+    protected double minValue;
+    protected double maxValue;
+
+    /** Allows input of discontinuous values with a certain step */
+    protected double stepSize;
+
+    protected boolean drawString;
+
+    private final DecimalFormat format;
+
+    /**
+     * @param x x position of upper left corner
+     * @param y y position of upper left corner
+     * @param width Width of the widget
+     * @param height Height of the widget
+     * @param prefix {@link Component} displayed before the value string
+     * @param suffix {@link Component} displayed after the value string
+     * @param minValue Minimum (left) value of slider
+     * @param maxValue Maximum (right) value of slider
+     * @param currentValue Starting value when widget is first displayed
+     * @param stepSize Size of step used. Precision will automatically be calculated based on this value if this value is not 0.
+     * @param precision Only used when {@code stepSize} is 0. Limited to a maximum of 4 (inclusive).
+     * @param drawString Should text be displayed on the widget
+     */
+    public ForgeSlider(int x, int y, int width, int height, Component prefix, Component suffix, double minValue, double maxValue, double currentValue, double stepSize, int precision, boolean drawString)
+    {
+        super(x, y, width, height, TextComponent.EMPTY, 0D);
+        this.prefix = prefix;
+        this.suffix = suffix;
+        this.minValue = minValue;
+        this.maxValue = maxValue;
+        this.stepSize = Math.abs(stepSize);
+        this.value = this.snapToNearest((currentValue - minValue) / (maxValue - minValue));
+        this.drawString = drawString;
+
+        if (stepSize == 0D)
+        {
+            precision = Math.min(precision, 4);
+
+            StringBuilder builder = new StringBuilder("0");
+
+            if (precision > 0)
+                builder.append('.');
+
+            while (precision-- > 0)
+                builder.append('0');
+
+            this.format = new DecimalFormat(builder.toString());
+        }
+        else if (Mth.equal(this.stepSize, Math.floor(this.stepSize)))
+        {
+            this.format = new DecimalFormat("0");
+        }
+        else
+        {
+            this.format = new DecimalFormat(Double.toString(this.stepSize).replaceAll("\\d", "0"));
+        }
+
+        this.updateMessage();
+    }
+
+    /**
+     * Overload with {@code stepSize} set to 1, useful for sliders with whole number values.
+     */
+    public ForgeSlider(int x, int y, int width, int height, Component prefix, Component suffix, double minValue, double maxValue, double currentValue, boolean drawString)
+    {
+        this(x, y, width, height, prefix, suffix, minValue, maxValue, currentValue, 1D, 0, drawString);
+    }
+
+    /**
+     * @return Current slider value as a double
+     */
+    public double getValue()
+    {
+        return this.value * (maxValue - minValue) + minValue;
+    }
+
+    /**
+     * @return Current slider value as an long
+     */
+    public long getValueLong()
+    {
+        return Math.round(this.getValue());
+    }
+
+    /**
+     * @return Current slider value as an int
+     */
+    public int getValueInt()
+    {
+        return (int) this.getValueLong();
+    }
+
+    /**
+     * @param value The new slider value
+     */
+    public void setValue(double value)
+    {
+        this.value = this.snapToNearest((value - this.minValue) / (this.maxValue - this.minValue));
+        this.updateMessage();
+    }
+
+    public String getValueString()
+    {
+        return this.format.format(this.getValue());
+    }
+
+    @Override
+    public void onClick(double mouseX, double mouseY)
+    {
+        this.setValueFromMouse(mouseX);
+    }
+
+    @Override
+    protected void onDrag(double mouseX, double mouseY, double dragX, double dragY)
+    {
+        super.onDrag(mouseX, mouseY, dragX, dragY);
+        this.setValueFromMouse(mouseX);
+    }
+
+    @Override
+    public boolean keyPressed(int keyCode, int scanCode, int modifiers)
+    {
+        boolean flag = keyCode == GLFW.GLFW_KEY_LEFT;
+        if (flag || keyCode == GLFW.GLFW_KEY_RIGHT)
+        {
+            if (this.minValue > this.maxValue)
+                flag = !flag;
+            float f = flag ? -1F : 1F;
+            if (stepSize <= 0D)
+                this.setSliderValue(this.value + (f / (this.width - 8)));
+            else
+                this.setValue(this.getValue() + f * this.stepSize);
+        }
+
+        return false;
+    }
+
+    private void setValueFromMouse(double mouseX)
+    {
+        this.setSliderValue((mouseX - (this.x + 4)) / (this.width - 8));
+    }
+
+    /**
+     * @param value Percentage of slider range
+     */
+    private void setSliderValue(double value)
+    {
+        double oldValue = this.value;
+        this.value = this.snapToNearest(value);
+        if (!Mth.equal(oldValue, this.value))
+            this.applyValue();
+
+        this.updateMessage();
+    }
+
+    /**
+     * Snaps the value, so that the displayed value is the nearest multiple of {@code stepSize}.
+     * If {@code stepSize} is 0, no snapping occurs.
+     */
+    private double snapToNearest(double value)
+    {
+        if(stepSize <= 0D)
+            return Mth.clamp(value, 0D, 1D);
+
+        value = Mth.lerp(Mth.clamp(value, 0D, 1D), this.minValue, this.maxValue);
+
+        value = (stepSize * Math.round(value / stepSize));
+
+        if (this.minValue > this.maxValue)
+        {
+            value = Mth.clamp(value, this.maxValue, this.minValue);
+        }
+        else
+        {
+            value = Mth.clamp(value, this.minValue, this.maxValue);
+        }
+
+        return Mth.map(value, this.minValue, this.maxValue, 0D, 1D);
+    }
+
+    @Override
+    protected void updateMessage()
+    {
+        if (this.drawString)
+        {
+            this.setMessage(new TextComponent("").append(prefix).append(this.getValueString()).append(suffix));
+        }
+        else
+        {
+            this.setMessage(TextComponent.EMPTY);
+        }
+    }
+
+    @Override
+    protected void applyValue() {}
+}

src/main/java/net/minecraftforge/client/gui/widget/Slider.java

@@ -16,8 +16,13 @@
 /**
  * This class is blatantly stolen from iChunUtils with permission.
  *
+ * @deprecated This class has a few issues,
+ * mainly <a href="https://github.com/MinecraftForge/MinecraftForge/issues/8485">MinecraftForge/MinecraftForge#8485</a>.
+ * Use {@link ForgeSlider} instead.
+ *
  * @author iChun
  */
+@Deprecated(since = "1.18.2", forRemoval = true)
 public class Slider extends ExtendedButton
 {
     /** The value of this slider control. */