add stuff from docs

(cherry picked from commit 943b4de)

src/main/java/com/cleanroommc/modularui/drawable/DrawableSerialization.java

@@ -13,6 +13,7 @@
 import com.google.gson.JsonSerializationContext;
 import com.google.gson.JsonSerializer;
 import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
 
 import java.lang.reflect.Type;
 import java.util.ArrayList;
@@ -25,7 +26,7 @@ public class DrawableSerialization implements JsonSerializer<IDrawable>, JsonDes
 
     private static final Map<String, Function<JsonObject, IDrawable>> DRAWABLE_TYPES = new HashMap<>();
 
-    public static void registerDrawableType(String id, Function<JsonObject, IDrawable> creator) {
+    public static void registerDrawableType(String id, Function<@NotNull JsonObject, @NotNull IDrawable> creator) {
         if (DRAWABLE_TYPES.containsKey(id)) {
             throw new IllegalArgumentException("Drawable type '" + id + "' already exists!");
         }
@@ -41,6 +42,8 @@ public static void init() {
         registerDrawableType("rectangle", json -> new Rectangle());
         registerDrawableType("ellipse", json -> new Circle());
         registerDrawableType("text", DrawableSerialization::parseText);
+        registerDrawableType("item", ItemDrawable::ofJson);
+        registerDrawableType("icon", Icon::ofJson);
     }
 
     @Override

src/main/java/com/cleanroommc/modularui/drawable/Icon.java

@@ -4,7 +4,9 @@
 import com.cleanroommc.modularui.api.drawable.IIcon;
 import com.cleanroommc.modularui.screen.viewport.GuiContext;
 import com.cleanroommc.modularui.utils.Alignment;
+import com.cleanroommc.modularui.utils.JsonHelper;
 import com.cleanroommc.modularui.widget.sizer.Box;
+import com.google.gson.JsonObject;
 import cpw.mods.fml.relauncher.Side;
 import cpw.mods.fml.relauncher.SideOnly;
 
@@ -14,7 +16,7 @@
 public class Icon implements IIcon {
 
     private final IDrawable drawable;
-    private int width = 18, height = 18;
+    private int width = 0, height = 0;
     private Alignment alignment = Alignment.Center;
     private final Box margin = new Box();
 
@@ -60,12 +62,12 @@ public Alignment getAlignment() {
     }
 
     public Icon width(int width) {
-        this.width = width;
+        this.width = Math.max(0, width);
         return this;
     }
 
     public Icon height(int height) {
-        this.height = height;
+        this.height = Math.max(0, height);
         return this;
     }
 
@@ -116,4 +118,32 @@ public Icon marginBottom(int val) {
         this.margin.bottom(val);
         return this;
     }
+
+    @Override
+    public void loadFromJson(JsonObject json) {
+        this.width = (json.has("autoWidth") || json.has("autoSize")) &&
+                JsonHelper.getBoolean(json, true, "autoWidth", "autoSize") ? 0 :
+                JsonHelper.getInt(json, 0, "width", "w", "size");
+        this.height = (json.has("autoHeight") || json.has("autoSize")) &&
+                JsonHelper.getBoolean(json, true, "autoHeight", "autoSize") ? 0 :
+                JsonHelper.getInt(json, 0, "height", "h", "size");
+        this.alignment = JsonHelper.deserialize(json, Alignment.class, Alignment.Center, "alignment", "align");
+        this.margin.all(JsonHelper.getInt(json, 0, "margin"));
+        if (json.has("marginHorizontal")) {
+            this.margin.left = json.get("marginHorizontal").getAsInt();
+            this.margin.right = this.margin.left;
+        }
+        if (json.has("marginVertical")) {
+            this.margin.top = json.get("marginVertical").getAsInt();
+            this.margin.bottom = this.margin.top;
+        }
+        this.margin.top = JsonHelper.getInt(json, this.margin.top, "marginTop");
+        this.margin.bottom = JsonHelper.getInt(json, this.margin.bottom, "marginBottom");
+        this.margin.left = JsonHelper.getInt(json, this.margin.left, "marginLeft");
+        this.margin.right = JsonHelper.getInt(json, this.margin.right, "marginRight");
+    }
+
+    public static Icon ofJson(JsonObject json) {
+        return JsonHelper.deserialize(json, IDrawable.class, IDrawable.EMPTY, "drawable", "icon").asIcon();
+    }
 }

src/main/java/com/cleanroommc/modularui/drawable/ItemDrawable.java

@@ -3,15 +3,24 @@
 import com.cleanroommc.modularui.api.drawable.IDrawable;
 import com.cleanroommc.modularui.screen.GuiScreenWrapper;
 import com.cleanroommc.modularui.screen.viewport.GuiContext;
+import com.cleanroommc.modularui.utils.GameObjectHelper;
+import com.cleanroommc.modularui.utils.JsonHelper;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
 import cpw.mods.fml.relauncher.Side;
 import cpw.mods.fml.relauncher.SideOnly;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.RenderHelper;
 import net.minecraft.client.renderer.entity.RenderItem;
 import net.minecraft.item.ItemStack;
-import org.jetbrains.annotations.Nullable;
+import net.minecraft.nbt.JsonToNBT;
+import net.minecraft.nbt.NBTException;
+import net.minecraft.nbt.NBTTagCompound;
 import org.lwjgl.opengl.GL11;
 
+import javax.annotation.Nullable;
+import java.util.NoSuchElementException;
+
 public class ItemDrawable implements IDrawable {
 
     private ItemStack item = null;
@@ -51,4 +60,35 @@ public ItemDrawable setItem(@Nullable ItemStack item) {
         this.item = item;
         return this;
     }
+
+    public static ItemDrawable ofJson(JsonObject json) {
+        String itemS = JsonHelper.getString(json, null, "item");
+        if (itemS == null) throw new JsonParseException("Item property not found!");
+        String[] parts = itemS.split(":");
+        if (parts.length < 2)
+            throw new JsonParseException("Item property must have be in the format 'mod:item_name:meta'");
+        int meta = 0;
+        if (parts.length > 2) {
+            try {
+                meta = Integer.parseInt(parts[2]);
+            } catch (NumberFormatException e) {
+                throw new JsonParseException(e);
+            }
+        }
+        ItemStack item;
+        try {
+            item = GameObjectHelper.getItemStack(parts[0], parts[1], meta);
+        } catch (NoSuchElementException e) {
+            throw new JsonParseException(e);
+        }
+        if (json.has("nbt")) {
+            try {
+                NBTTagCompound nbt = (NBTTagCompound) JsonToNBT.func_150315_a(JsonHelper.getObject(json, new JsonObject(), o -> o, "nbt").toString());
+                item.setTagCompound(nbt);
+            } catch (NBTException e) {
+                throw new JsonParseException(e);
+            }
+        }
+        return new ItemDrawable(item);
+    }
 }

src/main/java/com/cleanroommc/modularui/utils/GameObjectHelper.java

@@ -0,0 +1,21 @@
+package com.cleanroommc.modularui.utils;
+
+import cpw.mods.fml.common.registry.GameRegistry;
+import net.minecraft.init.Items;
+import net.minecraft.item.ItemStack;
+
+import java.util.NoSuchElementException;
+
+public class GameObjectHelper {
+
+    public static ItemStack getItemStack(String mod, String path) {
+        return getItemStack(mod, path, 0);
+    }
+
+    public static ItemStack getItemStack(String mod, String path, int meta) {
+        ItemStack item = GameRegistry.findItemStack(mod, path, 1);
+        if (item == null) throw new NoSuchElementException("Item '" + mod + ":" + path + "' was not found!");
+        Items.feather.setDamage(item, meta);
+        return item;
+    }
+}