Object: added support for templates (#54)

Co-authored-by: Lauris BH <lauris@nix.lv>

tmx_object.go

@@ -25,6 +25,7 @@ package tiled
 import (
 	"encoding/xml"
 	"errors"
+	"path/filepath"
 	"strconv"
 	"strings"
 )
@@ -69,6 +70,9 @@ func (g *ObjectGroup) DecodeObjectGroup(m *Map) {
 			// won't be loaded.
 			m.TileGIDToTile(object.GID)
 		}
+		if len(object.TemplateSource) > 0 {
+			object.initTemplate(m)
+		}
 	}
 }
 
@@ -119,6 +123,41 @@ type Object struct {
 	PolyLines []*PolyLine `xml:"polyline"`
 	// Text
 	Text *Text `xml:"text"`
+	// Template
+	TemplateSource string `xml:"template,attr"`
+	TemplateLoaded bool   `xml:"-"`
+	Template       *Template
+}
+
+func (o *Object) initTemplate(m *Map) error {
+	if o.TemplateLoaded {
+		return nil
+	}
+	if len(o.TemplateSource) == 0 {
+		o.TemplateLoaded = true
+		return nil
+	}
+	sourcePath := m.GetFileFullPath(o.TemplateSource)
+	f, err := m.loader.open(sourcePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	d := xml.NewDecoder(f)
+	if err := d.Decode(&o.Template); err != nil {
+		return err
+	}
+	o.TemplateLoaded = true
+
+	if o.Template == nil || o.Template.Tileset == nil || o.Template.Object == nil {
+		return nil
+	}
+	if src := o.Template.Tileset.Source; len(src) > 0 {
+		// The tileset source may be relative from the template location.
+		o.Template.Tileset.Source = filepath.Join(filepath.Dir(o.TemplateSource), src)
+	}
+	return m.initTileset(o.Template.Tileset)
 }
 
 // UnmarshalXML decodes a single XML element beginning with the given start element.

tmx_template.go

@@ -0,0 +1,29 @@
+/*
+Copyright (c) 2021 Lauris Bukšis-Haberkorns <lauris@nix.lv>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+package tiled
+
+// Template is used for custom properties.
+type Template struct {
+	Tileset *Tileset `xml:"tileset"`
+	Object  *Object  `xml:"object"`
+}