conversation: support files drag and drop

Change-Id: If97d5b8602ab162b605b1df02c9528d6609d4f0c
diff --git a/ui/Base.lproj/FileToSendCollectionItem.xib b/ui/Base.lproj/FileToSendCollectionItem.xib
new file mode 100644
index 0000000..e74c4fa
--- /dev/null
+++ b/ui/Base.lproj/FileToSendCollectionItem.xib
@@ -0,0 +1,154 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="17701" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="17701"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <objects>
+        <customObject id="-2" userLabel="File's Owner" customClass="FileToSendCollectionItem">
+            <connections>
+                <outlet property="closeButton" destination="VNn-a7-nCL" id="Fir-qs-MIO"/>
+                <outlet property="fileName" destination="ijl-x9-Fsc" id="ayy-3D-Pku"/>
+                <outlet property="filePreview" destination="MNG-EM-Qlk" id="G1Y-8c-e1F"/>
+                <outlet property="fileSize" destination="3gS-G1-CGL" id="phJ-aQ-Jc4"/>
+                <outlet property="placeholderPreview" destination="2xL-sU-hKn" id="kzn-2u-kcL"/>
+                <outlet property="view" destination="Hz6-mo-xeY" id="0bl-1N-x8E"/>
+            </connections>
+        </customObject>
+        <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
+        <customObject id="-3" userLabel="Application" customClass="NSObject"/>
+        <customView id="Hz6-mo-xeY">
+            <rect key="frame" x="0.0" y="0.0" width="237" height="142"/>
+            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+            <subviews>
+                <box boxType="custom" borderType="line" cornerRadius="5" title="Box" titlePosition="noTitle" translatesAutoresizingMaskIntoConstraints="NO" id="ooj-cE-stw">
+                    <rect key="frame" x="1" y="7" width="235" height="128"/>
+                    <view key="contentView" id="ZpE-Xm-M0g">
+                        <rect key="frame" x="1" y="1" width="233" height="126"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <stackView distribution="fill" orientation="horizontal" alignment="top" spacing="5" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" detachesHiddenViews="YES" translatesAutoresizingMaskIntoConstraints="NO" id="842-Qz-SVo">
+                                <rect key="frame" x="5" y="5" width="224" height="116"/>
+                                <subviews>
+                                    <customView translatesAutoresizingMaskIntoConstraints="NO" id="phf-cN-BzN">
+                                        <rect key="frame" x="0.0" y="58" width="58" height="58"/>
+                                        <subviews>
+                                            <imageView horizontalHuggingPriority="251" verticalHuggingPriority="251" translatesAutoresizingMaskIntoConstraints="NO" id="2xL-sU-hKn">
+                                                <rect key="frame" x="15" y="15" width="28" height="28"/>
+                                                <constraints>
+                                                    <constraint firstAttribute="height" constant="28" id="4Mw-Hv-6wd"/>
+                                                    <constraint firstAttribute="width" constant="28" id="RCW-uG-lDt"/>
+                                                </constraints>
+                                                <imageCell key="cell" refusesFirstResponder="YES" alignment="left" imageScaling="proportionallyUpOrDown" id="VDv-mw-XOU"/>
+                                            </imageView>
+                                            <imageView horizontalHuggingPriority="251" verticalHuggingPriority="251" translatesAutoresizingMaskIntoConstraints="NO" id="MNG-EM-Qlk">
+                                                <rect key="frame" x="3" y="3" width="53" height="53"/>
+                                                <constraints>
+                                                    <constraint firstAttribute="height" constant="53" id="LJ5-mB-Y0x"/>
+                                                    <constraint firstAttribute="width" constant="53" id="URP-ZM-yCO"/>
+                                                </constraints>
+                                                <imageCell key="cell" refusesFirstResponder="YES" alignment="left" imageScaling="proportionallyUpOrDown" id="20B-vl-GyZ"/>
+                                            </imageView>
+                                        </subviews>
+                                        <constraints>
+                                            <constraint firstItem="2xL-sU-hKn" firstAttribute="centerY" secondItem="phf-cN-BzN" secondAttribute="centerY" id="73X-KJ-u04"/>
+                                            <constraint firstItem="MNG-EM-Qlk" firstAttribute="leading" secondItem="phf-cN-BzN" secondAttribute="leading" constant="3" id="Oiu-7c-qlC"/>
+                                            <constraint firstAttribute="height" constant="58" id="Q5V-9L-zfN"/>
+                                            <constraint firstItem="2xL-sU-hKn" firstAttribute="centerX" secondItem="phf-cN-BzN" secondAttribute="centerX" id="bRD-yP-pk6"/>
+                                            <constraint firstAttribute="width" constant="58" id="eTv-Rm-moB"/>
+                                            <constraint firstItem="MNG-EM-Qlk" firstAttribute="centerY" secondItem="phf-cN-BzN" secondAttribute="centerY" id="wWK-Lw-tSI"/>
+                                        </constraints>
+                                    </customView>
+                                    <customView translatesAutoresizingMaskIntoConstraints="NO" id="LMb-Cj-Jk0">
+                                        <rect key="frame" x="63" y="0.0" width="136" height="116"/>
+                                        <subviews>
+                                            <stackView distribution="fill" orientation="vertical" alignment="leading" spacing="5" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" detachesHiddenViews="YES" translatesAutoresizingMaskIntoConstraints="NO" id="Hmo-oU-oaN">
+                                                <rect key="frame" x="0.0" y="40" width="33" height="36"/>
+                                                <subviews>
+                                                    <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ijl-x9-Fsc">
+                                                        <rect key="frame" x="-2" y="20" width="37" height="16"/>
+                                                        <constraints>
+                                                            <constraint firstAttribute="width" relation="lessThanOrEqual" constant="120" id="ciw-pN-NqF"/>
+                                                        </constraints>
+                                                        <textFieldCell key="cell" lineBreakMode="truncatingTail" title="Label" id="Rn4-fV-6rv">
+                                                            <font key="font" metaFont="system"/>
+                                                            <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
+                                                            <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
+                                                        </textFieldCell>
+                                                    </textField>
+                                                    <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="3gS-G1-CGL">
+                                                        <rect key="frame" x="-2" y="0.0" width="35" height="15"/>
+                                                        <textFieldCell key="cell" lineBreakMode="truncatingTail" title="Label" id="dVy-YN-Jio">
+                                                            <font key="font" metaFont="systemLight" size="12"/>
+                                                            <color key="textColor" red="0.0" green="0.0" blue="0.0" alpha="0.7987211044520548" colorSpace="custom" customColorSpace="sRGB"/>
+                                                            <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
+                                                        </textFieldCell>
+                                                    </textField>
+                                                </subviews>
+                                                <visibilityPriorities>
+                                                    <integer value="1000"/>
+                                                    <integer value="1000"/>
+                                                </visibilityPriorities>
+                                                <customSpacing>
+                                                    <real value="3.4028234663852886e+38"/>
+                                                    <real value="3.4028234663852886e+38"/>
+                                                </customSpacing>
+                                            </stackView>
+                                        </subviews>
+                                        <constraints>
+                                            <constraint firstItem="Hmo-oU-oaN" firstAttribute="centerY" secondItem="LMb-Cj-Jk0" secondAttribute="centerY" id="mCm-Ia-h36"/>
+                                            <constraint firstItem="Hmo-oU-oaN" firstAttribute="leading" secondItem="LMb-Cj-Jk0" secondAttribute="leading" id="wKD-q7-S47"/>
+                                        </constraints>
+                                    </customView>
+                                    <button translatesAutoresizingMaskIntoConstraints="NO" id="VNn-a7-nCL">
+                                        <rect key="frame" x="204" y="96" width="20" height="20"/>
+                                        <constraints>
+                                            <constraint firstAttribute="height" constant="20" id="2HM-Sa-2IJ"/>
+                                            <constraint firstAttribute="width" constant="20" id="NH1-93-gER"/>
+                                        </constraints>
+                                        <buttonCell key="cell" type="square" bezelStyle="shadowlessSquare" image="ic_action_cancel" imagePosition="only" alignment="center" imageScaling="proportionallyUpOrDown" inset="2" id="vA9-gd-tcb">
+                                            <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                            <font key="font" metaFont="system"/>
+                                        </buttonCell>
+                                        <color key="contentTintColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
+                                    </button>
+                                </subviews>
+                                <constraints>
+                                    <constraint firstAttribute="bottom" secondItem="LMb-Cj-Jk0" secondAttribute="bottom" id="W5l-Ui-hrJ"/>
+                                    <constraint firstItem="LMb-Cj-Jk0" firstAttribute="top" secondItem="842-Qz-SVo" secondAttribute="top" id="Yj6-Ld-0rs"/>
+                                </constraints>
+                                <visibilityPriorities>
+                                    <integer value="1000"/>
+                                    <integer value="1000"/>
+                                    <integer value="1000"/>
+                                </visibilityPriorities>
+                                <customSpacing>
+                                    <real value="3.4028234663852886e+38"/>
+                                    <real value="3.4028234663852886e+38"/>
+                                    <real value="3.4028234663852886e+38"/>
+                                </customSpacing>
+                            </stackView>
+                        </subviews>
+                        <constraints>
+                            <constraint firstAttribute="trailing" secondItem="842-Qz-SVo" secondAttribute="trailing" constant="4" id="0pO-kb-AGR"/>
+                            <constraint firstItem="842-Qz-SVo" firstAttribute="leading" secondItem="ZpE-Xm-M0g" secondAttribute="leading" constant="5" id="Pw2-d1-elQ"/>
+                            <constraint firstItem="842-Qz-SVo" firstAttribute="top" secondItem="ZpE-Xm-M0g" secondAttribute="top" constant="5" id="baT-0U-3bY"/>
+                            <constraint firstAttribute="bottom" secondItem="842-Qz-SVo" secondAttribute="bottom" constant="5" id="sHs-RI-UwE"/>
+                        </constraints>
+                    </view>
+                    <color key="borderColor" name="quaternaryLabelColor" catalog="System" colorSpace="catalog"/>
+                </box>
+            </subviews>
+            <constraints>
+                <constraint firstItem="ooj-cE-stw" firstAttribute="leading" secondItem="Hz6-mo-xeY" secondAttribute="leading" constant="1" id="3Dc-MC-jW0"/>
+                <constraint firstAttribute="trailing" secondItem="ooj-cE-stw" secondAttribute="trailing" constant="1" id="ajy-Xr-VBD"/>
+                <constraint firstItem="ooj-cE-stw" firstAttribute="top" secondItem="Hz6-mo-xeY" secondAttribute="top" constant="7" id="b3b-lv-pPE"/>
+                <constraint firstAttribute="bottom" secondItem="ooj-cE-stw" secondAttribute="bottom" constant="7" id="isd-gP-ldD"/>
+            </constraints>
+            <point key="canvasLocation" x="-332.5" y="-27"/>
+        </customView>
+    </objects>
+    <resources>
+        <image name="ic_action_cancel" width="72" height="72"/>
+    </resources>
+</document>