Refactor app shortcut handling (#1392)

1 files changed, 106 insertions, 0 deletions

diff --git a/app/src/main/java/dev/msfjarvis/aps/util/shortcuts/ShortcutHandler.kt b/app/src/main/java/dev/msfjarvis/aps/util/shortcuts/ShortcutHandler.kt
new file mode 100644
index 00000000..8e36c9af
--- /dev/null
+++ b/app/src/main/java/dev/msfjarvis/aps/util/shortcuts/ShortcutHandler.kt
@@ -0,0 +1,106 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.util.shortcuts
+
+import android.content.Context
+import android.content.Intent
+import android.content.pm.ShortcutInfo
+import android.content.pm.ShortcutManager
+import android.graphics.drawable.Icon
+import android.os.Build
+import androidx.annotation.RequiresApi
+import androidx.core.content.getSystemService
+import com.github.ajalt.timberkt.d
+import dagger.Reusable
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dev.msfjarvis.aps.R
+import dev.msfjarvis.aps.data.password.PasswordItem
+import javax.inject.Inject
+
+@Reusable
+class ShortcutHandler
+@Inject
+constructor(
+  @ApplicationContext val context: Context,
+) {
+
+  private companion object {
+
+    // The max shortcut count from the system is set to 15 for some godforsaken reason, which
+    // makes zero sense and is why our update logic just never worked. Capping it at 4 which is
+    // what most launchers seem to have agreed upon is the only reasonable solution.
+    private const val MAX_SHORTCUT_COUNT = 4
+  }
+
+  /**
+   * Creates a
+   * [dynamic shortcut](https://developer.android.com/guide/topics/ui/shortcuts/creating-shortcuts#dynamic)
+   * that shows up with the app icon on long press. The list of items is capped to
+   * [MAX_SHORTCUT_COUNT] and older items are removed by a simple LRU sweep.
+   */
+  fun addDynamicShortcut(item: PasswordItem, intent: Intent) {
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N_MR1) return
+    val shortcutManager: ShortcutManager = context.getSystemService() ?: return
+    val shortcut = buildShortcut(item, intent)
+    val shortcuts = shortcutManager.dynamicShortcuts
+    // If we're above or equal to the maximum shortcuts allowed, drop the last item.
+    if (shortcuts.size >= MAX_SHORTCUT_COUNT) {
+      shortcuts.removeLast()
+    }
+    // Reverse the list so we can append our new shortcut at the 'end'.
+    shortcuts.reverse()
+    shortcuts.add(shortcut)
+    // Reverse it again, so the previous items are now in the correct order and our new item
+    // is at the front like it's supposed to.
+    shortcuts.reverse()
+    // Write back the new shortcuts.
+    shortcutManager.dynamicShortcuts = shortcuts.map(::rebuildShortcut)
+  }
+
+  /**
+   * Creates a
+   * [pinned shortcut](https://developer.android.com/guide/topics/ui/shortcuts/creating-shortcuts#pinned)
+   * which presents a UI to users, allowing manual placement on the launcher screen. This method is
+   * a no-op if the user's default launcher does not support pinned shortcuts.
+   */
+  fun addPinnedShortcut(item: PasswordItem, intent: Intent) {
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
+    val shortcutManager: ShortcutManager = context.getSystemService() ?: return
+    if (!shortcutManager.isRequestPinShortcutSupported) {
+      d { "addPinnedShortcut: pin shortcuts unsupported" }
+      return
+    }
+    val shortcut = buildShortcut(item, intent)
+    shortcutManager.requestPinShortcut(shortcut, null)
+  }
+
+  /** Creates a [ShortcutInfo] from [item] and assigns [intent] to it. */
+  @RequiresApi(Build.VERSION_CODES.N_MR1)
+  private fun buildShortcut(item: PasswordItem, intent: Intent): ShortcutInfo {
+    return ShortcutInfo.Builder(context, item.fullPathToParent)
+      .setShortLabel(item.toString())
+      .setLongLabel(item.fullPathToParent + item.toString())
+      .setIcon(Icon.createWithResource(context, R.drawable.ic_lock_open_24px))
+      .setIntent(intent)
+      .build()
+  }
+
+  /**
+   * Takes an existing [ShortcutInfo] and builds a fresh instance of [ShortcutInfo] with the same
+   * data, which ensures that the get/set dance in [addDynamicShortcut] does not cause invalidation
+   * of icon assets, resulting in invisible icons in all but the newest launcher shortcut.
+   */
+  @RequiresApi(Build.VERSION_CODES.N_MR1)
+  private fun rebuildShortcut(shortcut: ShortcutInfo): ShortcutInfo {
+    // Non-null assertions are fine since we know these values aren't null.
+    return ShortcutInfo.Builder(context, shortcut.id)
+      .setShortLabel(shortcut.shortLabel!!)
+      .setLongLabel(shortcut.longLabel!!)
+      .setIcon(Icon.createWithResource(context, R.drawable.ic_lock_open_24px))
+      .setIntent(shortcut.intent!!)
+      .build()
+  }
+}