Save last used perspective

Author: Dan Oprea

app/src/main/java/com/dan/perspective/MainActivity.kt

@@ -63,6 +63,7 @@ class MainActivity : AppCompatActivity() {
     private lateinit var inputImage: Mat
     private lateinit var outputImage: Mat
     private var menuSave: MenuItem? = null
+    private var menuPrevPerspective: MenuItem? = null
     private var editMode = true
 
     private val firstAnimatorListener = object : Animator.AnimatorListener {
@@ -184,8 +185,13 @@ class MainActivity : AppCompatActivity() {
 
     override fun onCreateOptionsMenu(menu: Menu?): Boolean {
         menuInflater.inflate(R.menu.main_menu, menu)
+
         menuSave = menu?.findItem(R.id.save)
         menuSave?.isEnabled = !inputImage.empty()
+
+        menuPrevPerspective = menu?.findItem(R.id.prevPerspective)
+        menuPrevPerspective?.isEnabled = !inputImage.empty() && settings.prevHeight > 0
+
         return true
     }
 
@@ -206,6 +212,32 @@ class MainActivity : AppCompatActivity() {
                 SettingsDialog.show(this)
                 return true
             }
+
+            R.id.prevPerspective -> {
+                if (settings.prevHeight < 1) return true
+                if (inputImage.empty()) return true
+
+                binding.imageEdit.setPerspective(
+                    PointF(
+                        settings.prevLeftTopX * inputImage.width() / settings.prevWidth,
+                        settings.prevLeftTopY * inputImage.height() / settings.prevHeight
+                    ),
+                    PointF(
+                        settings.prevRightTopX * inputImage.width() / settings.prevWidth,
+                        settings.prevRightTopY * inputImage.height() / settings.prevHeight
+                    ),
+                    PointF(
+                        settings.prevLeftBottomX * inputImage.width() / settings.prevWidth,
+                        settings.prevLeftBottomY * inputImage.height() / settings.prevHeight
+                    ),
+                    PointF(
+                        settings.prevRightBottomX * inputImage.width() / settings.prevWidth,
+                        settings.prevRightBottomY * inputImage.height() / settings.prevHeight
+                    )
+                )
+
+                return true;
+            }
         }
 
         return super.onOptionsItemSelected(item)
@@ -361,6 +393,7 @@ class MainActivity : AppCompatActivity() {
         binding.radioButtonPointDirectionVertical.isEnabled = enabled
 
         menuSave?.isEnabled = enabled
+        menuPrevPerspective?.isEnabled = enabled && settings.prevHeight > 0
     }
 
     private fun loadImage(uri: Uri) : Mat {
@@ -435,6 +468,21 @@ class MainActivity : AppCompatActivity() {
                     values.put(MediaStore.Images.Media.DATA, fileFullPath)
                     values.put(MediaStore.Images.Media.MIME_TYPE, "image/${outputExtension}")
                     contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
+
+                    val perspectivePoints = binding.imageEdit.getPerspective()
+                    settings.prevWidth = outputImage.width()
+                    settings.prevHeight = outputImage.height()
+                    settings.prevLeftTopX = perspectivePoints.pointLeftTop.x
+                    settings.prevLeftTopY = perspectivePoints.pointLeftTop.y
+                    settings.prevRightTopX = perspectivePoints.pointRightTop.x
+                    settings.prevRightTopY = perspectivePoints.pointRightTop.y
+                    settings.prevLeftBottomX = perspectivePoints.pointLeftBottom.x
+                    settings.prevLeftBottomY = perspectivePoints.pointLeftBottom.y
+                    settings.prevRightBottomX = perspectivePoints.pointRightBottom.x
+                    settings.prevRightBottomY = perspectivePoints.pointRightBottom.y
+                    settings.saveProperties()
+
+                    menuPrevPerspective?.isEnabled = true
                 }
 
                 showToast("Saved to: $fileName")

app/src/main/java/com/dan/perspective/Settings.kt

@@ -36,6 +36,16 @@ class Settings( private val activity: Activity) {
     var tiffDepth = DEPTH_AUTO
     var engineDepth = DEPTH_AUTO
     var hapticFeedback = true
+    var prevLeftTopX = -1f
+    var prevLeftTopY = -1f
+    var prevRightTopX = -1f
+    var prevRightTopY = -1f
+    var prevRightBottomX = -1f
+    var prevRightBottomY = -1f
+    var prevLeftBottomX = -1f
+    var prevLeftBottomY = -1f
+    var prevWidth = 0
+    var prevHeight = 0
 
     init {
         loadProperties()

app/src/main/res/menu/main_menu.xml

@@ -13,9 +13,14 @@
         android:title="Save"
         android:visibility="gone"
         app:showAsAction="always" />
+    <item
+        android:id="@+id/prevPerspective"
+        android:enabled="false"
+        android:title="Previous Perspective"
+        app:showAsAction="never" />
     <item
         android:id="@+id/settings"
         android:icon="@android:drawable/ic_menu_preferences"
         android:title="Settings"
-        app:showAsAction="always" />
+        app:showAsAction="never" />
 </menu>