1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "java_lang_builder.h"
18 
19 #include "android-base/stringprintf.h"
20 
21 using android::base::StringPrintf;
22 using std::string;
23 
Start() const24 void JavaLangViewBuilder::Start() const {
25   out_ << StringPrintf("package %s;\n", package_.c_str())
26        << "import android.content.Context;\n"
27           "import android.content.res.Resources;\n"
28           "import android.content.res.XmlResourceParser;\n"
29           "import android.util.AttributeSet;\n"
30           "import android.util.Xml;\n"
31           "import android.view.*;\n"
32           "import android.widget.*;\n"
33           "\n"
34           "public final class CompiledView {\n"
35           "\n"
36           "static <T extends View> T createView(Context context, AttributeSet attrs, View parent, "
37           "String name, LayoutInflater.Factory factory, LayoutInflater.Factory2 factory2) {"
38           "\n"
39           "  if (factory2 != null) {\n"
40           "    return (T)factory2.onCreateView(parent, name, context, attrs);\n"
41           "  } else if (factory != null) {\n"
42           "    return (T)factory.onCreateView(name, context, attrs);\n"
43           "  }\n"
44           // TODO: find a way to call the private factory
45           "  return null;\n"
46           "}\n"
47           "\n"
48           "  public static View inflate(Context context) {\n"
49           "    try {\n"
50           "      LayoutInflater inflater = LayoutInflater.from(context);\n"
51           "      LayoutInflater.Factory factory = inflater.getFactory();\n"
52           "      LayoutInflater.Factory2 factory2 = inflater.getFactory2();\n"
53           "      Resources res = context.getResources();\n"
54        << StringPrintf("      XmlResourceParser xml = res.getLayout(%s.R.layout.%s);\n",
55                        package_.c_str(),
56                        layout_name_.c_str())
57        << "      AttributeSet attrs = Xml.asAttributeSet(xml);\n"
58           // The Java-language XmlPullParser needs a call to next to find the start document tag.
59           "      xml.next(); // start document\n";
60 }
61 
Finish() const62 void JavaLangViewBuilder::Finish() const {
63   out_ << "    } catch (Exception e) {\n"
64           "      return null;\n"
65           "    }\n"  // end try
66           "  }\n"    // end inflate
67           "}\n";     // end CompiledView
68 }
69 
StartView(const string & class_name,bool)70 void JavaLangViewBuilder::StartView(const string& class_name, bool /*is_viewgroup*/) {
71   const string view_var = MakeVar("view");
72   const string layout_var = MakeVar("layout");
73   std::string parent = "null";
74   if (!view_stack_.empty()) {
75     const StackEntry& parent_entry = view_stack_.back();
76     parent = parent_entry.view_var;
77   }
78   out_ << "      xml.next(); // <" << class_name << ">\n"
79        << StringPrintf("      %s %s = createView(context, attrs, %s, \"%s\", factory, factory2);\n",
80                        class_name.c_str(),
81                        view_var.c_str(),
82                        parent.c_str(),
83                        class_name.c_str())
84        << StringPrintf("      if (%s == null) %s = new %s(context, attrs);\n",
85                        view_var.c_str(),
86                        view_var.c_str(),
87                        class_name.c_str());
88   if (!view_stack_.empty()) {
89     out_ << StringPrintf("      ViewGroup.LayoutParams %s = %s.generateLayoutParams(attrs);\n",
90                          layout_var.c_str(),
91                          parent.c_str());
92   }
93   view_stack_.push_back({class_name, view_var, layout_var});
94 }
95 
FinishView()96 void JavaLangViewBuilder::FinishView() {
97   const StackEntry var = view_stack_.back();
98   view_stack_.pop_back();
99   if (!view_stack_.empty()) {
100     const string& parent = view_stack_.back().view_var;
101     out_ << StringPrintf("      xml.next(); // </%s>\n", var.class_name.c_str())
102          << StringPrintf("      %s.addView(%s, %s);\n",
103                          parent.c_str(),
104                          var.view_var.c_str(),
105                          var.layout_params_var.c_str());
106   } else {
107     out_ << StringPrintf("      return %s;\n", var.view_var.c_str());
108   }
109 }
110 
MakeVar(std::string prefix)111 const std::string JavaLangViewBuilder::MakeVar(std::string prefix) {
112   std::stringstream v;
113   v << prefix << view_id_++;
114   return v.str();
115 }
116